106 publications

369 citations | h-index 9 | (As of June 2019)

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1. Effects of conscious sedation on tachycardia inducibility and patient comfort during ablation of supraventricular tachycardia. A randomized controlled study

Raja J. Selvaraj, Subash Dukiya, Ajith Ananthakrishna Pillai, Santhosh Satheesh, Jayaraman Balachander. Europace 2019; 21: 142-146

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Aims: Sedation is not consistently used during electrophysiology procedures because of concerns regarding effects on tachycardia inducibility. We designed this study to assess the effect of conscious sedation on tachycardia inducibility and patient comfort during supraventricular tachycardia ablation. Methods and results: Patients with narrow QRS tachycardia and no pre-excitation undergoing an electrophysiology study were randomly assigned to sedation or placebo group. Patients in the sedation group received intermittent doses of midazolam and fentanyl, while those in the placebo group received normal saline as placebo. The physician and the patient were blinded to the allocation. Information was collected on tachycardia inducibility, patient discomfort, and complications. A total of 103 patients were included in the study. Proportion of patients with difficult tachycardia induction (27.4% vs. 32.7%) or with non-inducibility (5.8% vs. 3.8%) were not different between the sedation and placebo groups. Patient discomfort as measured by the Wong-Baker scale was significantly less in the sedation group (1.45 ± 1.08 vs. 2.24 ± 1.2, P < 0.0007) compared to the placebo group. There was no difference in incidence of hypotension or hypoxia between the two groups. Conclusions: Conscious sedation with intermittent midazolam- and fentanyl-reduced patient discomfort during electrophysiology study and ablation of supraventricular tachycardia without affecting tachycardia inducibility. Sedation administered in the absence of an anaesthetist was safe.

2. Ablation of post-operative atrial flutter in the presence of interrupted IVC

Pramod N.Pawar and Raja J.Selvaraj. Indian Pacing and Electrophysiology Journal 2019; 19: 23-26

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3. Hydatid cyst of interventricular septum- A rare cause of Complete heart block

Raja Selvaraj, Bhagwati Pant, Ramesh A.. Indian Pacing and Electrophysiology Journal 2019; None: None

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4. An unusual form of preexcitation

Raja Selvaraj, Pramod Pawar, Devendra. Journal of Cardiovascular Electrophysiology 2019; None: None

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5. Procedural and follow-up clinical outcomes after chronic total occlusion revascularization: Data from an Indian public hospital

Ajith Ananthakrishna Pillai * , Sakthivel Ramasamy, Kabilan S. Jagadheesan, Santhosh Satheesh, Raja J. Selvaraj, Balachander Jayaraman. Indian Heart Journal 2019; None: None

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6. Body Surface Distribution of T wave alternans is Modulated by Heart Rate and Ventricular Activation Sequence in Patients with Cardiomyopathy

Vijay S. Chauhan; Behnaz Ghoraani; Adrian Suszko; Raja Selvaraj; Anandaraja Subramanian; Sridhar Krishnan. PLOS One 2019; None: None

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7. Device detected arrhythmias - Staying afloat in the data deluge

Girija Agarwal, Raja Selvaraj. Indian Pacing and Electrophysiology Journal 2019; None: None

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8. Upper loop reentrant flutter

Raja Selvaraj, Joseph Theodore. Europace 2019; None: None

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9. Long-term outcomes following left main bifurcation stenting in Indian population-Analysis based on SYNTAX I and II scores

Pillai, Ajith Ananthakrishna and {Gousy. V}, Saranya and Kottyath, Harichandrakumar and Satheesh, Santhosh and Selvaraj, Raja and Jayaraman, Balachander. Indian Heart Journal 2018; 70: 394-398

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Background: Syntax 1 and recently Syntax 2(SS2) scores are validated risk prediction models in coronary disease. Objectives: To find out the long term outcomes following stenting for unprotected left main bifurcation disease (LMD) and to validate and compare the performance of the SYNTAX scores 1 and 2(SS1 and SS2 PCI) for predicting major adverse cardiac events (MACE) in Indian population. Methods: Single-center, retrospective, observational study involving patients who underwent percutaneous coronary intervention (PCI) with at least one stent implanted for the LMD. Discrimination and calibration models were assessed by ROC curve and the Hosmer-Lemeshow test. Results: Data of 103 patients were analyzed. The mean SS1 and SS2 scores were 27.9 and 30.7 and MACE was 16.5{\%} at 4 years. The target lesion revascularization (TLR) rate at 4 years was 11(10.7{\%}). There were 4 deaths (3.8{\%}). The mean left ventricular ejection fraction (LV EF) was the only variable in SS2, which predicted cardiac events. ROC curve analysis showed both models to be accurate in predicting TLR and mortality following LM PCI. SS2 score showed a better risk prediction than SSI with AUC for TLR (SSI 0.560 and SS2PCI 0.625) and AUC for mortality (SS1 0.674 and SS2PCI 0.833). Hosmer-Lemeshow test validated the accuracy of both the risk models in predicting the events. Conclusions: Both risk models were applicable for Indian patients. The SS2 score was a better predictor for mortality and TLR. In the SS2 score, the LV EF was the most useful predictor of events after LM PCI.

10. Wide to narrow complex tachycardia: What is the diagnosis?

Rohit, Manojkumar and Krishnappa, Darshan and Selvaraj, Raja J.. Journal of Cardiovascular Electrophysiology 2018; 29: 487--488

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11. A young female with cyanosis and clubbing

Gupta, Praveen K. and Selvaraj, Raja J.. Eur J Intern Med. 2018; 54: e7

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12. Honeycomb-like appearance on optical coherence tomography in right coronary artery

Gupta, Praveen K. and Pillai, Ajith A. and Satheesh, Santhosh and Selvaraj, Raja and Balachander, Jayaram. The International Journal of Cardiovascular Imaging 2018; 34: 343--344

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13. Demonstration of dual AV nodal physiology - More than one way to skin a cat?

Selvaraj, Raja J.. Indian Pacing and Electrophysiology Journal 2018; 18: 47--48

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14. Biological Pacemakers - A review

Velvizhi G and Raja Selvaraj. International Journal of Cardiovascular Practice 2018; 3: None

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Slow heart rates, due to sinus node disease or atrioventricular conduction block, are a significant problem for many patients. Currently, these patients are treated with electronic pacemakers, which provide effective therapy, but are also associated with many problems. Use of biological pacemakers is an attractive solution to these problems. Approaches for the creation of such pacemakers include either the injection of cells that have pacemaker activity (cell-based approach) or modification of cells in the heart to induce pacemaker activity by delivering genes (gene-based approach). This article reviews the progress in the development of biological pacemakers.

15. Submitral Aneurysm in adults. A rare entity with varied presentations.

Baban Kumar, Santhosh Satheesh, Raja Selvaraj. Indian Heart Journal Case Reports 2018; 2: 119-122

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16. Percutaneous closure of iatrogenic arteriovenous fistula after pacemaker implantation

PK Gupta, Santhosh Satheesh and Raja Selvaraj. Heart Asia 2018; 10: e011072

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17. Low Power Ablation for Left Coronary Cusp Ventricular Tachycardia – Efficacy and Long Term Outcome

Jagadheesan KS, Satheesh S, Pillai AA, Jayaraman B, Selvaraj RJ. Indian Heart Journal 2018; 70: S384-S388

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18. Consensus statement for implantation and follow-up of cardiac implantable electronic devices in India

ShomuBohora, Amit Vora, Aditya Kapoor, Vanita Arora, Nitish Naik, Raja Selvaraj, Narayan Namboodiri, Anil Saxena, Ajay Naik, Balbir Singh, C.Narsimhan, Mohan Nair, T.S.Kler, Working committee Indian Heart Rhythm Society (IHRS). Indian Pacing and Electrophysiology Journal 2018; 18: 188-192

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Cardiac implantable electronic device (CIED) procedures are being done by many operators/centers and it is projected that this therapy will remarkably increase in India in the coming years. This document by IHRS, aims at guiding the Indian medical community in the appropriate use and method of implantation with emphasis on implanter training and center preparedness to deliver a safe and effective therapy to patients with cardiac rhythm disorders and heart failure.

19. Radiofrequency ablation of accessory pathways in Ebstein's anomaly

Selvaraj RJ. International Journal of Arrhythmia 2018; None: None

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20. Noninvasive Determination of HV Interval Using Magnetocardiography

Senthilnathan, Sengottuvel and Selvaraj, Raja J. and Patel, Rajesh and Satheesh, Santhosh and Katholil, Gireesan and Janawadkar, Madhukar P. and Radhakrishnan, Thimmakudy S.. PACE - Pacing and Clinical Electrophysiology 2017; 40: 568--577

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{\textcopyright} 2017 Wiley Periodicals, Inc. Background: The His-ventricular (HV) interval is an important index of atrioventricular conduction, but at present can be reliably measured only during an invasive electrophysiology (EP) study. Magnetocardiography (MCG) is a noninvasive measurement of weak magnetic fields generated by the heart. We compared HV interval noninvasively assessed using MCG with the corresponding values measured directly in an EP study. Methods: MCG was measured using a 37-channel system inside a magnetically shielded room in patients who had previously undergone an EP study. His-bundle potential was identified in the PR segment after signal averaging. Magnetic field maps representing the spatial distribution of ramp-like signals in the PR segment generated at various instants of time were used to identify His-bundle signals in cases where the deflection representing the His was ambiguous. Results: The study included 23 patients (14 male, nine female) with a wide range of HV intervals measured during EP study (49 ± 17 ms, range 35–120 ms). In 21 (91{\%}) subjects, discernible His-bundle signals are observed in the PR segment of MCG traces. HV intervals measured between the two methods showed a correlation (r 2 = 0.87, P {\textless} 0.0001) with a mean difference of 5.4 ± 3.2 ms. Conclusion: With the use of new criteria to identify the His-bundle deflection in signal-averaged MCG signals, we report a high success rate in noninvasive HV interval measurement and a good agreement with those from EP study. The results encourage the use of MCG as a noninvasive method for measurement of the HV interval.

21. Reuse of pacemakers, defibrillators and cardiac resynchronisation devices

Selvaraj, Raja J. and Sakthivel, R. and Satheesh, Santhosh and Pillai, Ajith Ananthakrishna and Sagnol, Pascal and Jouven, Xavier and Dodinot, Bernard and Balachander, Jayaraman. Heart Asia 2017; 9: 30--33

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OBJECTIVE Access to pacemakers remains poor among many patients in low/middle-income countries. Reuse of explanted pacemakers is a possible solution, but is still not widespread because of concerns regarding outcomes, especially infection. Our objective was to study early outcomes with implants using reused devices and compare them with those with implants using new devices. METHODS We studied all patients who underwent implantation of a new or reused pacemaker, cardiac resynchronisation therapy (CRT) device or implantable cardioverter defibrillator (ICD) in the last 5 years at a single institution. We analysed outcomes related to infection, device malfunction and device-related death within 6 months after initial implantation. RESULTS During the study period, 887 patients underwent device implant, including 127 CRT devices or ICDs. Of these, 260 devices (29.3{\%}) were reused and the others were new. At 6 months, there were three device-related infections in implants using a new device. There were no infections among patients receiving a reused device. There were no device malfunctions or device-related deaths in either group. CONCLUSIONS We found no difference in rate of infection or device malfunction among patients getting a reused device as compared with those with a new device. This study reinforces the safety of reusing devices for implant including CRT and ICDs.

  • Cited 11 times (Jun 2018)
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22. Infra-His Block during Atrial Pacing—Functional or Pathological?

Selvaraj, Raja J. and Kumar, Binay and Rangasamy, Sasinthar. PACE - Pacing and Clinical Electrophysiology 2017; 40: 69--71

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{\textcopyright} 2016 Wiley Periodicals, Inc. The significance of infra-His conduction abnormalities observed in the electrophysiology lab can be difficult to assess. In this report we show infra-His conduction block during programmed atrial stimulation in a patient and discuss if this should be considered functional or pathological.

23. Which side are you on? – Deducing the chamber of origin of atrial tachycardia

Selvaraj, Raja J. and Sarin, Krishna and Veeramani, Raveendranath. Indian Pacing and Electrophysiology Journal 2017; 17: 54--57

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Atrial arrhythmias rising from the regions of the atria that are in close proximity to each other may pose a challenge in identifying the chamber to map and ablate in. In this report, we discuss a patient with left atrial tachycardia which initially mimicked right atrial tachycardia. We discuss the origins of the abnormal electrograms in the right atrium and how this provides a general understanding of the mechanism of double potentials.

24. Clinical presentation, management, and outcomes in the Indian Heart Rhythm Society-Atrial Fibrillation (IHRS-AF) registry

Vora, A. and Kapoor, A. and Nair, M. and Lokhandwala, Y. and Narsimhan, C. and Ravikishore, A. G. and Dwivedi, S. K. and Namboodiri, N. and Hygriv, R. and Saxena, A. and Nabar, A. and Garg, S. and Bardoloi, N. and Yadav, R. and Nambiar, A. and Pandurangi, U. and Jhala, D. and Naik, A. and Nagmallesh and Rajagopal, S. and Selvaraj, R. and Arora, V. and Thachil, A. and Thomas, J. and Panicker, G.. Indian Heart Journal 2017; 69: 43--47

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Aim A national atrial fibrillation (AF) registry was conducted under the aegis of the Indian Heart Rhythm Society (IHRS), to capture epidemiological data-type of AF, clinical presentation and comorbidities, current treatment practices, and 1-year follow-up outcomes. Methods A total of 1537 patients were enrolled from 24 sites in India in the IHRS-AF registry from July 2011 to August 2012. Their baseline characteristics and follow-up data were recorded in case report forms and subsequently analyzed. Results The average age of Indian AF patients was 54.7 years. There was a marginal female preponderance – 51.5{\%} females and 48.5{\%} males. At baseline, 20.4{\%} had paroxysmal AF; 33{\%} had persistent AF; 35.1{\%} had permanent AF and 11{\%} had first AF episode. At one-year follow-up, 45.6{\%} patients had permanent AF. Rheumatic valvular heart disease (RHD) was present in 47.6{\%} of patients. Hypertension, heart failure, coronary artery disease, and diabetes were seen in 31.4{\%}, 18.7{\%}, 16.2{\%}, and 16.1{\%}, respectively. Rate control was the strategy used in 75.2{\%} patients, digoxin and beta-blockers being the most frequently prescribed rate-control drugs. Oral anticoagulation (OAC) drugs were used in 70{\%} of patients. The annual mortality was 6.5{\%}, hospitalization 8{\%}, and incidence of stroke 1{\%}. Conclusions In India, AF patients are younger and RHD is still the most frequent etiology. Almost two-third of the patients have persistent/permanent AF. At one-year follow-up, there is a significant mortality and morbidity in AF patients in India.

25. A deadly mix - rheumatic mitral stenosis, preexcited atrial fibrillation, left atrial appendage thrombus and left atrial appendage accessory pathway

Jagadheesan, K.S. and Rangasamy, S. and Selvaraj, R.J.. Indian Pacing and Electrophysiology Journal 2017; 17: 183-185

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26. Coronary Angiography Findings and Its Determinants in Patients Presenting With Acute Coronary Syndrome: A Descriptive Analysis from Asian Population

Chourasiya M, Satheesh S, Selvaraj R, Jayaraman B, Pillai AA.. Mymensingh Med J 2017; 26: 927-33

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The aim was to study the angiographic profile in patients presented as acute coronary syndrome and its relation with risk factors and comparison between genders. This prospective observational study was performed on total 352 patients of acute coronary syndrome were analyzed for various risk factors, angiographic pattern in Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, South India from January 2015 to July 2016. Mean age of presentation was 52.62±11.63 years. Male were 271(77.0%) and female were 81(23.0%). Majority of patients were STEMI (67.6%) followed by UA (24.4%) and NSTEMI (8%). Smoker was 117(33.3%) patients. Hypertensive were 124(35.2%) of patients and 149(42.3%) were diabetics. Family history of CAD was positive in 45(12.8%). On angiographic evaluation left main reference diameter was lower in females (4.02±0.72) than males (4.07±0.82). LAD was most commonly involved followed by RCA and LCX among all three group of acute coronary syndrome. Left main was least involved (8.3%). In STEMI SVD (40.3%) was most common presentation, after that DVD was seen in 22.3%, TVD in 10.5%, non-obstructive coronary was seen in 16% of patients and normal coronary was seen in 11% of patients. In UA 28%, 22.8%, 13.2%, 15.8%, 20.2% was seen in SVD, DVD, TVD, non-obstructive and normal coronary respectively. Long length coronary lesions (>20mm) were seen in majority in all type of acute coronary syndrome. Coronary lesion length was not associated with presentation acute coronary syndrome and genders. Male were most commonly presented as acute coronary syndrome. STEMI was most common presentation. Diabetic was most prevalent risk factor. SVD was most common angiographic pattern and LAD was most common involved arteries.

27. Intra vascular ultrasound findings in drug eluting stent restenosis following emergent PCI for acute coronary syndrome – Gender based analysis

Ajith Ananthakrishna Pillai, Saranya Gousy V, Raja J.Selvaraj, BalachanderJayaraman. Journal of Indian College of Cardiology 2017; 7: 78-84

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Optimal stent deployment attaining larger lumen area with image guidance (IVUS/OCT) may reduce the risk of re-stenosis. However imaging based optimization is often not performed in emergency procedures. We planned to prospectively evaluate intra vascular ultrasound (IVUS) findings in patients with in stent restenosis (ISR) who underwent emergency PCI for ACS. Methods To find out the intra vascular ultrasound findings in drug eluting stent restenosis (DES-ISR). We enrolled consecutive patients with DES-ISR who had index PCI for ACS (NSTEMI/STEMI). IVUS analysis of individual lesions was performed for sub optimal stent deployment. Results Of the 1823 patients who had ACS PCI during the 5-year period, 172 patients {74 (9.4%) females and 88 males (8.4%)} had ISR. Eighty-two lesions in women were compared with 84 ISR lesions men. Baseline characteristics were similar except for presence of diabetes mellitus and multivessel disease. Females had more focal ISR (48 focal, 34 diffuse) compared to males (23 focal, 61 diffuse) (P < 0.001). The prevalence {38(46%) females and 33(39%)} and IVUS pattern of different mechanical factors (MF) with suboptimal stent deployment was not different between both sexes (P = 0.2). Conclusions The occurrence of ISR was higher in women. Women had higher TLR and lower mean vessel size. In 46% of women and 39% men, a mechanical factor with sub optimal stent deployment was found. Longer stented length, diffuse disease, calcification and Type B/C lesion type were associated with under expanded and undersized stents.

28. Calcium channel blockers for AF.

Amit Handa and Raja Selvaraj. Atrial fibrillation update. A textbook of Cardiology 2017; None: None

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29. Radiofrequency ablation of posteroseptal accessory pathways associated with coronary sinus diverticula

Selvaraj, Raja J. and Sarin, Krishna and Singh, Vivek Raj and Satheesh, Santhosh and Pillai, Ajith Ananthakrishna and Kumar, Mahesh and Balachander, Jayaraman. Journal of Interventional Cardiac Electrophysiology 2016; 47: 253--259

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PURPOSE: Posteroseptal accessory pathways may be associated with a coronary sinus (CS) diverticulum. Our purpose was to describe the clinical characteristics, mapping and ablation of these pathways. METHODS: This was a retrospective study of all patients who underwent ablation of posteroseptal accessory pathways in a single centre. Patients with a diverticulum of the CS or one of its tributaries were included in group I, while the other patients formed group II. Clinical presentation, ablation procedure and outcome were compared between the two groups. RESULTS: A total of 51 patients were included, 16 in group I and 35 in group II. There were no significant differences in age or sex distribution. Atrial fibrillation (AF) and previous unsuccessful ablation were more common in group I. A negative delta wave in lead II was the ECG finding with best sensitivity and specificity for the presence of a diverticulum. A pathway potential was common at the successful site in group I, and the interval between local ventricular electrogram and delta wave onset was shorter (19.5 +/- 8 vs 33.1 +/- 7.6 ms, p {\textless} 0.001). There was a trend toward lower procedural success rate and higher recurrence rate in group I, although this was not significant. CONCLUSIONS: CS diverticula should be suspected in patients with manifest posteroseptal accessory pathways who have a previous failed ablation, documented AF or typical electrocardiographic signs. A discrete potential is frequently seen at the successful site, but the local ventricular electrogram is not as early as in other accessory pathways.

  • Cited 5 times (Jun 2018)
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30. Fighting sudden cardiac death in India – Knowing your enemy is half the battle

Selvaraj, Raja. Indian Pacing and Electrophysiology Journal 2016; 16: 120

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31. Change of Heart: Altered Atrial Activation Following an Atrial Extrastimulus

Selvaraj, Raja and Satheesh, Santhosh and Balachander, Jayaraman. None 2016; 27: 618--620

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32. Pathophysiology and pharmacology of cardiovascular disease

Selvaraj RJ. J Pharmacol Pharmacother 2016; 7: 55

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33. Atrioventricular junction ablation for rate control in atrial fibrillation

Amar Upadhyay and Raja Selvaraj. Practical Cardiac Electrophysiology 2016; None: None

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34. A Young Female with Recurrent Syncope

Raja Selvaraj, Mahadeva Swamy and Deepak Amalnathan. Heart Asia 2016; 8: 54-55

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35. Seckel Syndrome with Severe Sinus Bradycardia

Ramasamy, Chandramohan and Satheesh, Santhosh and Selvaraj, Raja. Indian Journal of Pediatrics 2015; 82: 292--293

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Seckel syndrome is an uncommon form of microcephalic dwarfism. The authors report a young boy with Seckel syndrome who presented with severe sinus bradycardia with symptoms of syncope and presyncope. Implantation of a permanent pacemaker was necessary in view of the severe symptoms. Although uncommon, cardiac abnormalities have been rarely reported in Seckel syndrome. This is the one of the few reports of rhythm abnormalities in this condition.

36. Jumping across the gap - A series of atrial extrastimuli

Swamy, Mahadeva and Katyal, Deepak and Selvaraj, Raja J.. Indian Pacing and Electrophysiology Journal 2015; 15: 73--75

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The ‘gap phenomenon' is an interesting phenomenon in electrophysiology arising from the differences in refractory periods at two or more levels of the atrioventricular (AV) conduction system. We present a patient with dual AV nodal physiology in whom the AH jump mediates the gap phenomenon. We also briefly discuss the other mechanisms of gap phenomenon that have been described in this setting.

37. Pace mapping in the atrium using bipolar electrograms from widely spaced electrodes

Selvaraj, Raja J. and Yerram, Sreekanth and Kumar, Pradeep and Satheesh, Santhosh and Pillai, Ajith Ananthakrishna and Saktheeswaran, Mahesh Kumar and Balachander, Jayaraman. Journal of Arrhythmia 2015; 31: 274--278

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Background Pace mapping is a useful tool but is of limited utility for the atrium because of poor spatial resolution. We investigated the use of bipolar electrograms recorded from widely spaced electrodes in order to improve the resolution of pace mapping. Methods This prospective study included patients undergoing a clinical electrophysiology study. Unipolar pacing from either the superior or inferior lateral right atrium was performed to simulate atrial tachycardia. Twelve-lead electrocardiograms were recorded during pacing as a template. In addition, three intracardiac bipolar electrograms from a set of widely spaced electrodes were also recorded. Subsequently, unipolar pacing was performed from electrodes at known distances from the initial pacing site, and the morphology of P waves in the electrocardiogram and bipolar electrograms were compared with that of the template. Morphological comparison was performed by a cardiologist and by automated computerized matching. Spatial resolution was calculated as the minimum distance at which there was no match. Results Fifteen patients participated in the study. Distance at which differences in morphology were noted was smaller in the bipolar electrograms compared to that indicated by P waves in the electrocardiogram, when matched by the cardiologist (6.1±3.8 mm vs. 9.9±5.2 mm, p=0.012) or by automated analysis (4±0 mm vs. 9.9±4 mm, p{\textless}0.001). Conclusions Use of three bipolar electrograms recorded from a set of widely spaced electrodes in the right atrium improves the resolution of pace mapping compared to that using P waves from surface electrocardiograms alone.

38. Cardiac syndrome X: Clinical characteristics revisited

Ezhumalai, Babu and Ananthakrishnapillai, Ajith and Selvaraj, Raja J. and Satheesh, Santhosh and Jayaraman, Balachander. Indian Heart Journal 2015; 67: 328--331

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Background Cardiac syndrome X includes a heterogenous group of patients with angina but normal epicardial coronaries in angiography. Objective Our objective was to study the clinical characteristics of patients with cardiac syndrome X. Methods Data of patients who underwent coronary angiography over a period of one year was retrospectively analyzed. Those with normal or non-obstructive coronaries in angiography with chest pain were included in this study. Results 1203 patients underwent coronary angiography during the study period. 105 (8.7{\%}) patients fulfilled the inclusion criteria. There were 52 (49.5{\%}) males and 53 (50.5{\%}) females including 31 (29.5{\%}) postmenopausal women. Many patients had atherosclerotic risk factors. Typical angina and atypical chest pain were reported by 63 (60{\%}) and 42 (40{\%}) patients, respectively. ECG was normal in 46 (43.8{\%}) and abnormal in 59 (56.2{\%}) patients. The most common abnormal finding in ECG was ST-T changes seen in 49 (46.7{\%}) patients. Regional wall motion abnormality with mild left ventricular systolic dysfunction was seen in 4 (3.8{\%}) patients while 101 (96.2{\%}) patients had normal ventricular function in echocardiography. TMT was positive for inducible ischemia in 35 (33.3{\%}) patients and inconclusive in 10 (9.5{\%}) patients. Angiography showed normal epicardial coronaries in 85 (80.9{\%}) patients. Conclusions Cardiac syndrome X constitutes a significant subset of patients undergoing coronary angiography. It is essential to identify and treat them specifically for microvascular angina. Many of them have atherosclerotic risk factors but their presentation is different from those with obstructive coronaries.

  • Cited 5 times (Jun 2018)
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39. Complete atrioventricular block in pregnancy: Report of seven pregnancies in a patient without pacemaker

Keepanasseril, Anish and Maurya, Dilip Kumar and Yavana, Suriya J. and Selvaraj, Raja. BMJ Case Reports 2015; 2015: None

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{\textcopyright} 2015 BMJ Publishing Group. All rights reserved. Obstetric management of a woman with a permanent pacemaker in situ is well reported in the literature; but those who present without pacing are still debatable. The necessity for setting the optimal timing or rate of temporary artificial pacing, specifically for labour, has not been objectively assessed. Temporary pacing in most cases reported in the literature might be to withstand the variations in haemodynamic status during delivery and labour. We report a case of a patient with complete heart block without any pacing who had seven pregnancies without any significant changes in haemodynamic status during labour and delivery. Managing a pregnancy without pacing might be an appropriate alternative for women without any underlying cardiac disorder, as it will not lead to significant changes in the haemodynamic system.

  • Cited 4 times (Jan 2015)
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40. Wide complex tachycardia: What is the mechanism?

Lehrmann, Heiko and Jadidi, Amir S. and Park, Chan Il and Arentz, Thomas and Weber, Reinhold. PACE - Pacing and Clinical Electrophysiology 2015; 38: 403--406

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41. Diagnostic Dilemma in a Narrow Complex Tachycardia

Selvaraj, Raja J. and {Raj Singh}, Vivek and Balachander, Jayaraman. PACE - Pacing and Clinical Electrophysiology 2015; 38: 887--890

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42. Syncope with heart disease - Provoke and see or wait and watch ?

Selvaraj, R.J.. Indian Pacing and Electrophysiology Journal 2015; 15: None

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{\textcopyright} 2015, Indian Pacing and Electrophysiology Group. All rights reserved. Syncope is common in the young, but is usually reflex syncope and has a benign outcome except in the setting of strucural heart disease which is uncommon in this age group. After decreasing in adulthood and middle age, incidence of syncope again peaks in older patients where it is more often a multifactorial problem that can be associated with significant morbidity and is difficult to manage.

43. Werner Syndrome with Heart Block

Selvaraj, Raja J. and Upadhyay, Amarnath. None 2015; 128: e33--e34

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44. ECG for beginners

Anandaraja Subramanian and Raja Selvaraj. ECG for beginners. Jaypee brothers 2015; None: None

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45. A curious alliance: Sinus nodal dysfunction precipitating atrioventricular block

Yerram, Sreekanth and Ramasamy, Chandramohan and Balachander, Jayaraman and Selvaraj, Raja J.. Journal of Arrhythmia 2014; 30: 208--210

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An elderly woman presented with recurrent syncope. Sinus bradycardia and sinoatrial block were seen on the electrocardiogram; however, PR interval prolongation after sinus pauses suggested atrioventricular conduction system disease. The occurrence of complete atrioventricular block after a pause during the electrophysiological study confirmed a diagnosis of paroxysmal atrioventricular block precipitated by sinus pauses secondary to sinus nodal disease.

46. Coronary sinus diameter by echocardiography to differentiate atrioventricular nodal reentrant tachycardia from atrioventricular reentrant tachycardia

Ezhumalai, Babu and Satheesh, Santhosh and Anantha, Ajith and Pakkirisamy, Gobu and Balachander, Jayaraman and Selvaraj, Raja J.. Cardiology Journal 2014; 21: 273--278

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BACKGROUND: Coronary sinus (CS) has been shown to be larger in patients with atrioventricular nodal reentrant tachycardia (AVNRT). We sought to determine if echocardiographically measured CS diameter can help identify the mechanism of tachycardia in patients with narrow complex tachycardia without preexcitation before the invasive electrophysiology study. METHODS: Forty four patients with documented narrow complex, short RP tachycardia who were scheduled for an electrophysiology study were included. Based on the electrophysiology study, patients were divided into those with AVNRT and those with a concealed accessory pathway and atrioventricular reentrant tachycardia (AVRT). Proximal CS diameter (CSp) measured at the ostium and mid CS diameter (CSm) 1 cm distal to the ostium using transthoracic echocardiography. RESULTS: CSp was significantly larger in patients with AVNRT than AVRT (14.1 +/- 5 vs. 9.9 +/- 2 mm, p {\textless} 0.0001). CSm diameter was not significantly different between the two groups. A cut-off of CSp {\textgreater} 11.2 mm identified AVNRT with a sensitivity of 92.6{\%} and specificity of 76.9{\%}. CSp was a better discriminant (AUC 0.89, 95{\%} CI 0.75-0.97) compared to age (AUC 0.74, 95{\%} CI 0.58-0.87) or tachycardia rate (AUC 0.60, 95{\%} CI 0.44-0.76). CONCLUSIONS: Echocardiographic measurement of the diameter of CS ostium can help in identifying the mechanism of the tachycardia before the invasive electrophysiology study.

  • Cited 4 times (Jun 2018)
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47. Techniques and outcomes of transcatheter closure of complex atrial septal defects-Single center experience

Pillai, Ajith Ananthakrishna and Satheesh, Santhosh and Pakkirisamy, Gobu and Selvaraj, Raja and Jayaraman, Balachander. Indian Heart Journal 2014; 66: 38--44

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Objective To prospectively study the techniques and outcomes of transcatheter closure of complex Atrial septal defects (ASD). Study design and settings Prospective single center study with experience in catheter closure of ASD. All patients with complex ASD suitable for device closure. Objective Analysis of outcomes of transcatheter closure of complex ASD in JIPMER Hospital over the past 5-year period. Methods Complex ASD was predefined and patients satisfying inclusion and exclusion criteria are included. All the patients had meticulous Transesophageal echocardiography (TEE) imaging beforehand. Modifications of the conventional techniques were allowed on a case per case basis according to operator preference. Successfully intervened patients were followed up clinically. Results Out of the 75 patients enrolled, 69 patients had successful device closure (success rate 92{\%}) despite challenging anatomy. Fifty-six (74{\%}) patients had ASD ≥25 mm. Fifteen patients (20{\%}) had defect size ≥35 mm and 20 patients (26.6{\%}) had devices implanted with ≥35 mm waist size. Fifty percent of patients had complete absence of aortic rim and 25{\%} had deficient posterior rim. Twenty percent of patients had malaligned septum. Mean follow up period was 3.2 years. Conclusions Trans catheter closure is feasible in anatomically complex substrates of Secundum ASD. Careful case selection, scrupulous imaging protocol, and expertise in modified techniques are mandatory for successful outcomes. Copyright {\textcopyright} 2013, Cardiological Society of India. All rights reserved.

  • Cited 8 times (Jun 2018)
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48. Heart failure and pulsus alternans an unusual presentation of first-degree heart block

Kandaswamy, Pradeep Kumar and Anantha, Ajith and Balachander, Jayaraman and Selvaraj, Raja J.. None 2014; 7: 227--228

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49. Peritricuspid reentrant ventricular tachycardia in Ebstein's anomaly

Kumar, Senthil and Subramanian, Anandaraja and Selvaraj, Raja J.. None 2014; 16: 1633

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  • Cited 3 times (Jun 2018)
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50. Chasing red herrings: Making sense of the colors while mapping

Selvaraj, Raja J. and Shankar, Bhima and Subramanian, Anandaraja and Nair, Krishnakumar. None 2014; 7: 553--556

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None

  • Cited 4 times (Jun 2018)
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51. Parasystole in a mahaim accessory pathway

Ramasamy, Chandramohan and Kumar, Senthil and Selvaraj, Raja J.. Indian Pacing and Electrophysiology Journal 2014; 14: 223--226

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Automaticity has been described in Mahaim pathways, both spontaneously and during radiofrequency ablation. We describe an unusual case of automatic rhythm from a Mahaim pathway presenting as parasystole. The parasystolic beats were also found to initiate tachycardia, resulting in initial presentation with incessant tachycardia and tachycardia induced cardiomyopathy.

52. Submitral aneurysm: A rare cause of ventricular tachycardia

Kumar, Pradeep and Balachander, Jayaraman and Selvaraj, Raja J.. None 2014; 4: 112--113

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None

  • Cited 2 times (Jun 2018)
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53. Balloon pulmonary valvuloplasty in adults: immediate and long-term outcomes

Ananthakrishna, A. and Balasubramonium, V R and Thazhath, H K and Saktheeshwaran, M. and Selvaraj, R. and Satheesh, S. and Jayaraman, B.. J Heart Valve Dis 2014; 23: 511--515

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BACKGROUND AND AIM OF THE STUDY: The study aim was to determine the immediate and long-term outcomes of balloon pulmonary valvuloplasty (BPV) in a large cohort of adult patients (aged {\textgreater}/= 18 years) with congenital valvular pulmonic stenosis. METHODS: A retrospective data analysis was conducted of the immediate and long-term outcomes of adult patients who had undergone BPV between 2000 and 2012 at a single tertiary care center. RESULTS: A total of 132 patients (mean age 27.7 years; 95{\%} CI 21.12-34.76) underwent BPV, with a mean follow up period of 5.7 years (95{\%} CI 4.37-6.98). Intervention resulted in successful BPV ({\textgreater} 50{\%} reduction in baseline gradient) in 124 patients (94{\%}), and a partially successful BPV (20-50{\%} reduction in baseline gradient) in eight patients (6{\%}). The mean right ventricular (RV) systolic pressure was decreased from 90.6 mmHg (95{\%} CI 84.90-96.33) to 50.9 mmHg (95{\%} CI 47.17-54.61) (p {\textless} 0.001), and the pulmonary valve (PV) gradient was reduced from 70.7 mmHg (95{\%} CI 65.12-76.22) to 29.0 mmHg (95{\%} CI 25.83-32.23) (p {\textless} 0.001). The mean percentage difference in PV gradient in both genders was 60.23{\%} in males and 57.44{\%} in females (95{\%} CI 55.33-65.12 and 55.32-61.56, respectively) (p {\textgreater} 0.05). Pulmonary valve regurgitation was reported in 17.4{\%} of patients, and was not related to either successful outcome or balloon size. The gradient reductions were maintained after five and 10 years of follow up. Two patients (1.5{\%}) developed restenosis that required repeat BPV. There was no referral for urgent surgery. CONCLUSION: BPV in adults produced excellent long-term clinical results, there being no gender-related difference in outcome. In addition, the need for reintervention was very low.

  • Cited 4 times (Jun 2018)
54. Balloon valvuloplasty in rheumatic aortic valve stenosis: immediate and long-term results

Pillai, Ajith Ananthakrishna and Ramasamy, Chandramohan and Saktheeshwaran, Maheshkumar and Selvaraj, Raja and Satheesh, Santhosh and Jayaraman, Balachander. Cardiovascular Intervention and Therapeutics 2014; 30: 45--50

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To study the immediate and long-term results of balloon aortic valvuloplasty (BAV) in a large cohort of patients with rheumatic valvular aortic stenosis. Single tertiary care center retrospective data analysis of immediate and long-term outcomes in patients following BAV from 2000 to 2008. Ninety-two patients with rheumatic aortic stenosis (AS) were studied who underwent BAV. Mean age of patients was 21.7 years (95 {\%} CI 14.3-28.9) with mean follow-up period of 5.7 years (±SD 1.3). Intervention resulted in successful BAV (more than 50 {\%} reduction in baseline gradient) in 79 (85.9 {\%}) subjects (Group A) and partially successful BPV ({\textless}50 {\%} reduction in baseline gradient) in 8 (8.7 {\%}) subjects (Group B). BAV failed in 5 (5.4 {\%}) subjects (Group C). Concomitant balloon mitral valvuloplasty was done in 23/92 cases. Mean left ventricular systolic pressure decreased from 165.6 (95 {\%} CI 142.7-196.3) to 110.9 mmHg (95 {\%} CI 92.1-129.6), (P {\textless} 0.001) and mean aortic valve (AV) gradient from 50.7 (95 {\%} CI 35.12-66.22) to 27.2 mmHg (95 {\%} CI 25.83-31.23), (P {\textless} 0.001). The mean change in ejection fraction and mean AV gradient were significantly different between success (Groups A and B) and failure groups (P {\textless} 0.001). Different grades of aortic regurgitation were noted in 32 (34.78 {\%}) patients post BAV (severe regurgitation in 2.18 {\%}). Anova post hoc analysis showed sustained gradient reductions at 1- and 5-year follow-up (P {\textgreater} 0.05). The need for surgery was much lower in Group A (2.5 {\%}) compared to Group B (50 {\%}) and C (100 {\%}). BAV is an effective treatment strategy in dominant AS in multi valvular rheumatic disease situations. Combined aortic and mitral valvuloplasty was performed in one-fourth of study patients.

  • Cited 4 times (Jun 2018)
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55. Utility of balloon assisted technique in trans catheter closure of very large (≥ 35 mm) atrial septal defects

Ajith Ananthakrishna Pillai, Vidhyakar Rangaswamy Balasubramanian, Raja Selvaraj, Maheshkumar Saktheeswaran, Santhosh Satheesh, Balachander Jayaraman. Cardiovascular diagnosis and therapy 2014; 4: 21

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Background Very few published data is available on the outcomes of balloon assisted techniques (BATs) for trans catheter closure (TCC) of very large (Defined as≥ 35 mm size) ostium secundum atrial septal defect (ASD). Objective To study the utility of BAT as against conventional techniques (CT) in TCC of very large ostium secundum ASD (≥ 35 mm) over the past 5-year period and to find out the association of different morphological features of the defects in relation to TCC outcomes.

56. An unusual response to para-Hisian pacing: what is the explanation?

Selvaraj, Raja J and Yerram, Sreekanth and Ramasamy, Chandramohan and Balachander, Jayaraman. Heart rhythm 2013; 10: 1586--8

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None

  • Cited 2 times (Jun 2018)
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57. "Pseudo PJRT" - Fast-slow av nodal reentrant tachycardia presenting with tachycardia-induced cardiomyopathy

Selvaraj, Raja and Ananthakrishnapillai, Ajith and Sadasivam, Ravishankar and Balachander, Jayaraman. PACE - Pacing and Clinical Electrophysiology 2013; 36: e4-6

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A 52-year-old woman presented with left ventricular (LV) dysfunction and incessant narrow complex tachycardia. Electrocardiogram and clinical picture were suggestive of a permanent form of junctional reciprocating tachycardia, but electrophysiology study showed the tachycardia to be a fast-slow form of atrioventricular nodal reentrant tachycardia (AVNRT). Slow pathway ablation terminated the tachycardia and the LV dysfunction resolved completely at follow-up. Fast-slow AVNRT has not been reported to present in incessant form, and the mechanism in this patient was absent retrograde fast pathway conduction resulting in easy initiation and maintenance of tachycardia. {\textcopyright}2011 Wiley Periodicals, Inc.

58. Transient bradycardia induced by thiopentone sodium: A unique challenge in the management of refractory status epilepticus

Sharma, Sushma and Nair, Pradeep P. and Murgai, Aditya and Selvaraj, Raja J.. BMJ Case Reports 2013; None: None

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Thiopentone sodium is one of the important drugs in the armamentarium for terminating refractory status epilepticus, a neurological emergency. We report a case of thiopentone-related bradycardia during the management of the new onset refractory status epilepticus in a young man, which was circumvented by prophylactic insertion of temporary pacemaker while thiopentone infusion was continued. A systematic approach was employed to manage the status epilepticus, including infusion of thiamine and glucose followed by antiepileptic drugs. The patient was ventilated and infused with lorazepam, phenytoin, sodium valproate, levetiracetam and midazolam followed by thiopentone sodium. With the introduction of thiopentone the seizures could be controlled but the patient developed severe bradycardia and junctional rhythm. The bradycardia disappeared when thiopentone was withdrawn and reappeared when the drug was reintroduced. Propofol infusion was tried with no respite in seizures. Later thiopentone sodium was reintroduced after inserting temporary cardiac pacemaker. Seizure was controlled and patient was weaned off the ventilator.

  • Cited 2 times (Jun 2018)
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59. Premature ventricular complexes and left atrial appendage dysfunction - Another head on a many-headed hydra?

Selvaraj, Raja J.. Indian Pacing and Electrophysiology Journal 2013; 13: 134--135

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None

  • Cited 3 times (Jun 2018)
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60. Anomalous left anterior descending artery from pulmonary artery: An extremely rare coronary anomaly

George, K. Geofi and Gobu, Pakkirisamy and Selvaraj, Raja and Balachander, Jayaraman. Indian Heart Journal 2013; 65: 88--90

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We report a rare coronary artery anomaly-anomalous origin of the left anterior descending artery from the pulmonary artery in a 40-year-old woman. The uniqueness of this case is the absence of any significant morbidity from this condition in adulthood which is in contrast to other reported cases where patients present with myocardial infarction, congestive heart failure, and sometimes death during the early infantile period.1 {\textcopyright} 2012, Cardiological Society of India. All rights reserved.

61. Sequential anterograde and retrograde conduction block during radiofrequency ablation of an accessory pathway

Ramasamy, Chandramohan and Ramteke, Rahul and Balachander, Jayaraman and Selvaraj, Raja J.. Indian Pacing and Electrophysiology Journal 2013; 13: 148--150

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We present an interesting image showing sequential loss of anterograde, and subsequently, retrograde conduction during radiofrequency ablation of an accessory pathway. We discuss the possible mechanisms and prior literature concerning this interesting finding.

62. Ventricular tachycardia in repaired double chambered right ventricle - identification of the substrate and successful ablation

Selvaraj, Raja J. and Gobu, Pakkirisamy and Ashida, Thulaseedharan S. and George, Geofi and Balachander, Jayaraman. Indian Pacing and Electrophysiology Journal 2012; 12: 27--31

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A 35 year old female presented with recurrent ventricular tachycardia 5 years after she had undergone surgical repair of double chambered right ventricle. Electroanatomical mapping showed a localised scar in the apex with double potentials and good pace map. Ablation here resulted in non-inducibility of ventricular tachycardia. We hypothesise that the scarring in the apex is the result of sustained pressure overload and becomes arrhythmogenic similar to the apical scar in patients with mid-ventricular hypertrophic cardiomyopathy.

  • Cited 5 times (Jun 2018)
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63. Ablation of atrioventricular nodal reentrant tachycardia using the superior approach in a patient with IVC interruption

Vidhyakar, Balasubramanian and Sadasivam, Ravishankar and Balachander, Jayaraman and Selvaraj, Raja J.. None 2012; 23: 1393--1394

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64. Pseudodisappearance of atrial electrogram during accessory pathway ablation

Selvaraj, Raja and Santhosh, Satheesh and Balachander, Jayaraman. None 2012; 14: 993

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65. Latent Microvolt T wave Alternans in Survivors of Unexplained Cardiac Arrest Unmasked by Epinephrine Challenge.

Spears, Danna A and Suszko, Adrian M and Krahn, Andrew and Selvaraj, Raja J and Ivanov, Joan and Chauhan, Vijay S. Heart rhythm : the official journal of the Heart Rhythm Society 2012; None: None

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BACKGROUND: The arrhythmogenic substrate in survivors of unexplained cardiac arrest (UCA) has not been defined. OBJECTIVES: We tested the hypothesis that UCA patients have latent repolarization abnormalities, in particular T wave alternans (TWA), which may be unmasked with epinephrine (EPI) challenge. METHODS: We prospectively studied 10 UCA survivors (46±9 yr) and 11 first degree relatives (FDR) of sudden death victims (37±14 yr). UCA patients underwent standard clinical testing which was normal. FDR had normal clinical history and testing. All subjects underwent an EPI infusion (0.05, 0.1, 0.2 ug/kg/min, 5 min each dose) while recording continuous digital 12-lead ECGs. QTc and QT variability index (QTVI) were evaluated at each EPI dose. TWA magnitude (V(alt)) was assessed at each dose using the spectral method. Positive (+) TWA at each dose was defined as V (alt) {\textgreater}0 with k ≥3 in one or more 128-beat segment in ≥2 ECG leads. A novel metric, TWA burden, reflecting V(alt) integrated over time (s), was also evaluated for each EPI dose. RESULTS: There was no difference between UCA and FDR with respect to heart rate, QT, QTc, or QTVI at baseline or during EPI. At baseline, +TWA was similar between UCA and FDR (10 vs. 0{\%}, p=NS). During EPI, +TWA was more prevalent in UCA than FDR (80 vs. 18{\%}, p=0.009). TWA burden was greater in the UCA than FDR during EPI 0.1 (p=0.039) and EPI 0.2 ug/kg/min (p=0.009). CONCLUSIONS: UCA survivors are more likely to demonstrate latent TWA compared to FDR, which becomes manifest with epinephrine. This novel finding provides evidence for an arrhythmogenic substrate in UCA survivors.

  • Cited 2 times (Jun 2018)
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66. Electrocardiogram in mitral stenosis

Krishnakumar Nair, Diego Chemello and Raja Selvaraj. Percutaneous Mitral Valvotomy 2012; None: None

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67. Modulated dispersion of activation and repolarization by premature beats in patients with cardiomyopathy at risk of sudden death

Subramanian, A. and Suszko, A. and Selvaraj, R. J. and Nanthakumar, K. and Ivanov, J. and Chauhan, V. S.. AJP: Heart and Circulatory Physiology 2011; 300: H2221--H2229

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Premature beats can trigger ventricular arrhythmias in heart disease, but the mechanisms are not well defined. We studied the effect of premature beats on activation and repolarization dispersion in seven patients with cardiomyopathy (57 ± 10 yr, left ventricular ejection fraction 31 ± 7{\%}). Activation time (AT), activation-recovery interval (ARI), and total repolarization time (TRT) were measured from 26 unipolar electrograms during right ventricle (RV) endocardial (early) to left ventricle epicardial (late) activation in response to RV apical extrastimulation (S1S2). Early TRT dispersion increased significantly with shorter S1S2 (1.0 ± 0.2 to 2.3 ± 0.4 ms/mm, P {\textless} 0.0001), with minimal change in late TRT dispersion (0.8 ± 0.1 to 1.0 ± 0.3 ms, P = 0.02). This was associated with an increase in early AT dispersion (1.0 ± 0.1 to 1.5 ± 0.2 ms/mm, P = 0.05) but no change in late AT dispersion (0.6 ± 0.1 to 0.7 ± 0.2 ms/mm, P = 0.4). Early and late ARI dispersion did not change with shorter S1S2. AT restitution slopes were similar between early and late sites, as was slope heterogeneity. ARI restitution slope was greater in early vs. late sites (1.3 ± 0.6 vs. 0.8 ± 0.6, P = 0.03), but slope heterogeneity was similar. With shorter S1S2, AT-ARI slopes became less negative (flattened) at both early (-0.4 ± 0.1 to +0.04 ± 0.2) and late (-1.5 ± 0.2 to +0.3 ± 0.2) sites, implying less activation-repolarization coupling. There was no difference in AT-ARI slopes between early and late sites at short S1S2. In conclusion, high-risk patients with cardiomyopathy have greater TRT dispersion at tightly coupled S1S2 due to greater AT dispersion and activation-repolarization uncoupling. Modulated dispersion is more pronounced at early vs. late activated sites, which may predispose to reentrant ventricular arrhythmias.

  • Cited 6 times (Jun 2018)
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68. Effects of cleistanthins A and B on blood pressure and electrocardiogram in Wistar rats

Parasuraman, Subramani and Raveendran, Ramasamy and Selvaraj, Raja J.. Zeitschrift fur Naturforschung 2011; 66: 581--587

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We have studied the effects of cleistanthin A and cleistanthin B, phytoconstituents isolated from the leaves of Cleistanthus collinus Roxb. (Euphorbiaceae), on blood pressure, electrocardiogram, and barium chloride-induced arrhythmia in Wistar rats. The two compounds were isolated by column chromatography and their identity was confirmed spectroscopically. A healthy, male Wistar rat was used to record the invasive blood pressure and electrocardiograph. The antiarrhythmic effects of cleistanthins A and B were studied using the barium chloride model. Both cleistanthin A and cleistanthin B showed a dose-dependent hypotensive effect. Both compounds reduced the mean blood pressure significantly although the dose required for the effect was higher in the case of cleistanthin B. In the electrocardiogram, cleistanthins A and B significantly altered the electrical activity of the heart, the changes were transient and of no further consequence. Intravenous injection of 64 microg or more of cleistanthins A and B caused a sudden respiratory depression without affecting the electrocardiogram. Cleistanthins A and B did not display any antiarrhythmic effect against barium chloride-induced arrhythmia. In conclusion, both cleistanthin A and cleistanthin B exert a hypotensive effect and have no antiarrhythmic effect against barium chloride-induced arrhythmia in Wistar rats.

69. To the editor-his capture and entrainment

Nair, Krishnakumar and Selvaraj, Raja and Ho, Kah Len and Nanthakumar, Kumaraswamy. None 2011; 8: None

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None

  • Cited 2 times (Jun 2018)
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70. T wave alternans evaluation using adaptive time-frequency signal analysis and non-negative matrix factorization

Ghoraani, Behnaz and Krishnan, Sridhar and Selvaraj, Raja J. and Chauhan, Vijay S.. Medical Engineering and Physics 2011; 33: 700--711

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Each year 400,000 North Americans die from sudden cardiac death (SCD). Identifying those patients at risk of SCD remains a formidable challenge. T wave alternans (TWA) evaluation is emerging as an important tool to risk stratify patients with heart diseases. TWA is a heart rate dependent phenomenon that manifests on the surface electrocardiogram (ECG) as a change in the shape or amplitude of the T wave every second heart beat. The presence of large magnitude TWA often presages lethal ventricular arrhythmias. Because the TWA signal is typically in the microvolt range, accurate detection algorithms are required to control for confounding noise and changing physiological conditions (i.e. data nonstationarity). In this study, we address the limitations of two common TWA estimation methods, spectral method (SM) and modified moving average (MMA). To overcome their limitations, we propose a modified TWA quantification framework, called Adaptive SM, that uses non-linear time-frequency distribution (TFD). In order to increase the robustness of TWA detection in ambulatory ECGs, we also propose a new technique, called non-negative matrix factorization (NMF)-Adaptive SM. We present the analytical background of these methods, and evaluate their accuracy in detecting synthetic TWA signal in simulated and real-world ambulatory ECG recordings under conditions of noise and data non-stationarity. The results of the numerical simulations support the effectiveness of the proposed approaches for TWA analysis, which may ultimately improve SCD risk assessment. {\textcopyright} 2011 IPEM.

71. Ablation of ventricular tachycardia arising from the left coronary cusp

Selvaraj, Raja J. and Santhosh, Satheesh and Balachander, Jayaraman. Heart 2011; 97: 1720

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None

72. Microscopic systolic pressure alternans in human cardiomyopathy: Noninvasive evaluation of a novel risk marker and correlation with microvolt T-wave alternans

Selvaraj, Raja J. and Suszko, Adrian and Subramanian, Anandaraja and Mak, Susanna and Wainstein, Rodrigo and Chauhan, Vijay S.. Heart Rhythm 2011; 8: 236-243

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Background In patients with severe left ventricular (LV) dysfunction, visible pulsus alternans coincides with visible T-wave alternans (TWA), but a similar relationship has not been described for nonvisible microscopic systolic pressure alternans (MSPA) and microvolt TWA (MTWA). Objective The purpose of this study was to determine the prevalence of MSPA and its relationship to MTWA in patients with cardiomyopathy. Methods Using the spectral method, MSPA was measured from finger pressure during incremental atrial pacing and then validated against MSPA measured from the LV pressure in 12 patients. In 23 other patients with cardiomyopathy (LV ejection fraction {\textless}40{\%}), noninvasive MSPA and MTWA were measured simultaneously during incremental atrial pacing. Results MSPA ({\textless}1 mm Hg) was detected in 80{\%} of patients with cardiomyopathy and in 43{\%} of controls. The presence of finger MSPA showed 100{\%} positive concordance with LV MSPA; however, finger MSPA was 20{\%} larger due to peripheral augmentation. Finger MSPA was highly concordant (96{\%} positive concordance and 90{\%} negative concordance) with MTWA. The magnitudes of MSPA and MTWA showed a linear correlation (R = 0.66, P {\textless}.001), and the k value, a measure of signal-to-noise ratio, was significantly larger for MSPA compared to MTWA (108 ± 88 vs 24 ± 48, P {\textless}.001). Premature beats resulted in concordant and coincident changes in MSPA and MTWA. During follow-up (454 ± 274 days), 2 (8.6{\%}) patients experienced ventricular tachycardia, and both manifested MSPA and MTWA during pacing at 600 ms. Conclusion MSPA can be detected noninvasively in patients with cardiomyopathy and is coupled to MTWA, suggesting a common mechanism. The high signal-to-noise ratio of MSPA may provide a novel robust metric of sudden cardiac death risk in these patients. {\textcopyright} 2011 Heart Rhythm Society. All rights reserved.

73. T-wave alternans monitoring in patients with acute coronary syndrome--letter to the editor

Selvaraj, Raja. Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology: Journal of the Working Groups on Cardiac Pacing, Arrhythmias, and Cardiac Cellular Electrophysiology of the European Society of Cardiology 2011; 13: None

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74. Termination of a broad complex tachycardia by a premature atrial complex

Selvaraj, Raja and Arunprasath, Palamalai and Babu, Ezhumalai and Balachander, Jayaraman. None 2011; 22: 100

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75. Anodal stimulation-the intrigue continues

Selvaraj, Raja and Nair, Krishnakumar. Indian Pacing and Electrophysiology Journal 2011; 11: 61--63

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None

  • Cited 3 times (Jun 2018)
76. To the editor - Atrioventricular nodal reentrant tachycardia termination with two consecutive P waves

Selvaraj, Raja J. and Nair, Krishnakumar. None 2011; 8: None

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None

77. Multiple inappropriate rate drop responses triggered by ventricular premature beats

Babu, Ezhumalai and George, Geofi and Balachander, Jayaraman and Selvaraj, Raja. Europace 2011; 13: 1046

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We report the case of a 70-year-old patient presenting with palpitations who was found to have recurrent inappropriate rate drop responses on interrogation of his pacemaker. These were found to be triggered by interpolated premature ventricular complexes (PVCs). We discuss the drop detect algorithm and how interpolated PVCs triggered the rate drop response.

  • Cited 2 times (Jun 2018)
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78. To the editor-ICD implantation early after myocardial infarction

Selvaraj, Raja and Nair, Krishnakumar. None 2011; 8: None

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79. Prevention of postoperative atrial fibrillation - a stitch in time

Selvaraj, R.. Indian Pacing Electrophysiol J 2011; 10: 526--528

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None

  • Cited 3 times (Jun 2018)
80. Edited chapters 1,2,3,4 and 5

Selvaraj RJ. Leo Schamroth. An Introduction to Electrocardiography 2011; None: None

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81. Antidromic his capture during entrainment of orthodromic AVRT: EP ROUNDS

Nair, K. and Selvaraj, R. and Farid, T. and Nanthakumar, K.. PACE - Pacing and Clinical Electrophysiology 2010; 33: None

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A narrow QRS tachycardia with eccentric atrial activation is presented with features favoring an orthodromic atrioventricular re-entrant tachycardia including an extranodal paraHisian response, and a short corrected post-pacing interval to tachycardia cycle length difference following right ventricular entrainment. However, during entrainment, the H-H interval was entrained by the pacing train several beats prior to the A-A interval which would suggest an atrioventricular nodal re-entry tachycardia. We discuss the diagnosis and its mechanism. {\textcopyright} 2010 Wiley Periodicals, Inc.

  • Cited 5 times (Jun 2018)
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82. Does apd gradient indicate dispersion of repolarization?

Selvaraj, Raja J. and Nair, Krishnakumar. None 2010; 107: None

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83. Letter regarding "Assessment of physiological amplitude, duration and magnitude of ECG T-wave alternans"

Selvaraj, Raja J. Annals of Noninvasive Electrocardiology: The Official Journal of the International Society for Holter and Noninvasive Electrocardiology, Inc 2010; 15: 184; author reply 185--186

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84. A tale of four atrioventricular intervals

Subramanian, Anandaraja and Selvaraj, Raja J. and Cameron, Douglas. Europace 2010; 12: 441--442

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The introduction of new pacing algorithms for preserving intrinsic atrioventricular conduction has made the interpretation of normal pacemaker function at times challenging. Electrocardiographic (ECG) findings in a patient with apparent pacemaker malfunction is presented and interpretation given. During this process, the managed ventricular pacing algorithm is described to interpret the ECG findings and the potential pitfalls of this algorithm is discussed.

  • Cited 4 times (Jun 2018)
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85. "Locked-in" sensitivity in the managed ventricular pacing mode

Nair, Krishnakumar and Selvaraj, Raja and Watkins, Sheila and Cameron, Douglas. Heart Rhythm 2010; 7: 852--855

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Two cases of "locked-in" sensitivity in the managed ventricular pacing mode are reported. Patient A was a 22-year-old man with a history of hypertrophic obstructive cardiomyopathy and a prophylactic dual-chamber automatic implantable cardioverter-defibrillator who manifested paradoxic T-wave oversensing on the ventricular lead at a sensitivity setting of 1.2 mV but not earlier when the sensitivity had been set to 0.9 mV. Patient B was a 74-year-old patient with ischemic cardiomyopathy and a dual-chamber defibrillator who presented with persistent paradoxic undersensing of the P wave on the atrial lead even at the maximal sensitivity of 0.15 mV, although P-wave sensing was normal earlier when sensitivity was set to 0.3 mV. The phenomenon and the mechanism for its behavior are described. {\textcopyright} 2010 Heart Rhythm Society.

  • Cited 3 times (Jun 2018)
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86. A single atrial extrastimulus during a short RP tachycardia

Selvaraj, Raja and Nair, Krishnakumar and Subramanian, Anandaraja and Nanthakumar, Kumaraswamy. Heart Rhythm 2010; 7: 997--998

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87. Uncommon presentation of a common tachycardia

Raja J Selvaraj, Palamalai Arunprasath, Balakrishnan Karthikeyan, Geofi George, Jayaraman Balachander.. Indian Pacing and Electrophysiol J 2010; 10: 426-428

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None

  • Cited 6 times (Jun 2018)
88. Adaptive time-frequency matrix features for T wave alternans analysis

Ghoraani, Behnaz and Krishnan, Sridhar and Selvaraj, Raja J. and Chauhan, Vijay S.. Engineering in Medicine and Biology Society 2009; None: 39--42

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T wave alternans (TWA) has been associated with ventricular arrhythmias. Hence, TWA detection can risk stratify patients with heart disease who may experience sudden death from ventricular arhythmias. However, accurate TWA detection is technically challenging due to the low microvolt TWA signal and the confounding effect of biological noise such as movement, myopotentials or respiration. In this paper, we propose nonnegative matrix factorization (NMF)-Adaptive spectral method to increase the robustness of TWA detection in ambulatory electrocardiograms (ECGs). The proposed method applies a non-linear time-frequency (TF) analysis and NMF to the aligned ST-T waveforms. This method separates the TWA signal from the other non-desired ECG signal components, and detects TWA with high accuracy. The performance of our proposed method is validated in a clinical study using ECGs which confirms a TWA detection of 92{\%} compared to 47{\%} using the conventional spectral method.

89. Adrenergic stimulation increases repolarization dispersion and reduces activation-repolarization coupling along the RV endocardium of patients with cardiomyopathy

Selvaraj, Raja J. and Suszko, Adrian M. and Subramanian, Anandaraja and Nanthakumar, Kumaraswamy and Chauhan, Vijay S.. Europace 2009; 11: 1529--1535

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AIMS: Dispersion of repolarization (DOR) in the human heart is minimized by activation-repolarization coupling. Adrenergic stimulation can be proarrhythmic in patients with impaired left-ventricular function and its effect on repolarization dispersion has not been systematically investigated. Our objective was to study the effect of dobutamine on repolarization dispersion and activation-repolarization coupling in patients with cardiomyopathy. METHODS AND RESULTS: Activation recovery intervals (ARI) and activation times (AT) were measured from unipolar electrograms at 10 sites along the apicobasal right ventricle (RV) in 14 patients with cardiomyopathy (LVEF {\textless} 40{\%}). These measurements were made during control, dobutamine 2.5-5.0 microg/kg/min, and a recontrol phase while maintaining constant heart rates with atrial pacing. Dispersion of repolarization was calculated from the total recovery time (TRT, AT+ARI). Activation-repolarization coupling was assessed by linear regression of ARI and AT. Dispersion of repolarization across all 10 sites and between adjacent sites increased with dobutamine compared with control (whole DOR: range 15 +/- 2 vs. 12 +/- 2 ms, P = 0.06 and standard deviation 5.5 +/- 0.9 vs. 4.3 +/- 0.9 ms, P = 0.04; adjacent DOR: 5.9 +/- 0.8 vs. 4.5 +/- 0.6 ms, P = 0.04). This was associated with shallower ARI/AT slopes (-0.3 +/- 0.2 vs. -0.8 +/- 0.2, P = 0.05) and a decrease in ARI-AT correlation (R(2) 0.4 +/- 0.1 vs. 0.6 +/- 0.1, P = 0.05) with dobutamine compared with control. CONCLUSION: Adrenergic stimulation increases apicobasal RV DOR and reduces coupling between activation and repolarization in patients with cardiomyopathy. This may provide a mechanism for the proarrhythmic potential of heightened adrenergic states in these patients.

90. Defibrillator shock due to ventricular trigeminy

Nair, Krishnakumar and Selvaraj, Raja and Chauhan, Vijay S.. Europace 2009; 11: 374--375

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A 56-year-old lady with arrhythmogenic right ventricular cardiomyopathy had a shock for ventricular trigeminy. The device diagnosed this as ventricular fibrillation because of its binning algorithm, which does not use a consecutive, or a proportional counter. A beat is binned as a fibrillation beat only if the current cycle length is in the fibrillation zone and the running average of the previous four cycle lengths are in the fibrillation or ventricular tachycardia zone. Reprogramming the device into a single detection zone will help prevent shocks in this situation.

91. Wide Complex Tachycardia with RR and QRS Alternans : What Is the Mechanism ?

Anandaraja Subramanian, Raja J Selvaraj, Krishnakumar Nair, Kumaraswamy Nanthakumar. Pacing and clinical electrophysiology 2009; 32: 1329--1332

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None

  • Cited 2 times (Jun 2018)
  • DOI
92. Adaptive time-frequency signal analysis and its case study in biomedical ecg waveform analysis

Ghoraani, Behnaz and Krishnan, Sridhar and Selvaraj, Raja J. and Chauhan, Vijay D.. None 2009; None: None

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Traditional time-frequency (TF) signal representations are not appropriate for parametric analysis ofmost real world signals. In this study, we describe Adaptive time-frequency distribution (TFD) as a robust approach to TF signal decomposition for non-stationary signal processing. This approach has not been utilized for TF signal analysis other than feature extraction. We introduce T wave altemans (TWA) analysis as a new application for this approach. In order to test the robustness of the proposed technique, we challenge it under conditions of non-stationary dynamics that are expected with real world TWA. The results of the numerical simulation support the effectiveness of this approach for TWA estimation. {\textcopyright} 2009 IEEE.

  • Cited 5 times (Jun 2018)
  • DOI
93. The dangling electrogram: Discerning spatial from electrophysiological distance: Arrhythmia rounds

Selvaraj, Raja and Nair, Krishnakumar and Subramanian, Anandaraja and Nanthakumar, Kumaraswamy. Journal of Cardiovascular Electrophysiology 2009; 20: 1176--1178

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94. Body surface projection of action potential duration alternans: A combined clinical-modeling study with implications for improving T-wave alternans detection

Selvaraj, Raja J. and Suszko, Adrian M. and Subramanian, Anandaraja and Sivananthan, Dhinesh and Hill, Ann and Nanthakumar, Kumaraswamy and Chauhan, Vijay S.. Heart Rhythm 2009; 6: 1211--1219

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Background: Action potential duration alternans (APDA) can vary regionally in magnitude and phase. The influence of APDA heterogeneity on T-wave alternans (TWA) has not been defined. Objective: Our objectives were: (1) to determine how APDA affects the magnitude and spatial distribution of TWA, and (2) to optimize electrocardiographic (ECG) lead configuration accordingly to improve TWA detection. Methods: Global, regional, and discordant APDA were simulated in a 257-node heart model. Using a forward solution, body surface potentials were derived at 300 points on the thorax and TWA was computed at each point. In 22 patients with cardiomyopathy (left ventricular ejection fraction 28{\%} ± 6{\%}), TWA was measured from a 114-electrode body surface map using the spectral method during atrial pacing at 110 beats/min. Results: An increase in global APDA from 4 to 12 ms resulted in an increase in maximum TWA from 10 to 30 $\mu$V. TWA magnitude varied with the size and location of the alternating myocardium, but was largest with discordant APDA compared with regional or global APDA. Irrespective of the location or phase of APDA, TWA was largest over the precordium and correlated with T-wave amplitude in the simulation (R2= 0.56 ± 0.24, P {\textless}.01) and clinical study (R2= 0.45 ± 0.23, P {\textless}.02). A novel lead configuration (12 precordial leads + limb leads) significantly improved maximum TWA detection compared with the conventional 12-lead ECG+ Frank lead configuration. Conclusion: TWA magnitude is dependent on the interaction of concordant and discordant alternating sources within the heart. Maximum TWA consistently localizes to the precordium and a novel lead configuration using 12 precordial leads improves TWA quantification. {\textcopyright} 2009 Heart Rhythm Society.

95. Apparent ventricular lead malfunction - What is the mechanism?

Nair, Krishnakumar and Selvaraj, Raja and Chauhan, Vijay S.. Journal of Cardiovascular Electrophysiology 2009; 20: 110--112

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None

96. To the Editor-T wave alterans

Madias, John E.. None 2009; 6: None

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None

97. Effect of noise on t-wave alternans measurement in ambulatory ecgs using modified moving average versus spectral method

Selvaraj, Raja J. and Chauhan, Vijay S.. PACE - Pacing and Clinical Electrophysiology 2009; 32: 632--641

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BACKGROUND The modified moving average (MMA) and spectral method (SM) are commonly used to measure T-wave alternans (TWA), but their accuracy has not been compared in ambulatory electrocardiograms (ECGs) where TWA signal-to-noise ratio is low. Our objective was to compare the effect of noise and signal nonstationarity on the accuracy of TWA measurement using MMA versus SM when applied to synthetic and ambulatory ECGs. METHODS Periodic and nonperiodic noise were added to noiseless synthetic ECGs. Simulated TWA (0-20 microV) was added to synthetic ECGs and ambulatory ECG recordings. TWA was measured using SM and MMA, and the measurement error relative to added TWA was compared. An MMA ratio was used to discriminate TWA signal from noise. Signal nonstationarity was simulated by changing heart rate, TWA magnitude, and TWA phase. RESULTS With no added TWA, MMA falsely measured TWA in synthetic and ambulatory ECGs, while false measurement was not seen with SM. An MMA ratio {\textgreater} 1.2 eliminated false TWA detection. In the presence of low TWA magnitude ({\textless}10 microV), TWA was overestimated by MMA and underestimated by SM in proportion to the noise level. In synthetic ECGs with periodic noise and 10-microV added TWA, MMA was less accurate than SM. The effects of simulated signal nonstationarity on the TWA magnitude measured with MMA versus SM were similar using a 64-beat analysis window. CONCLUSIONS In the presence of noise, MMA falsely detects or overestimates simulated TWA in ambulatory ECG recordings. In this setting, the proposed MMA ratio improves the specificity of MMA.

  • Cited 6 times (Jun 2018)
  • DOI
98. Short-Term Memory and Restitution During Ventricular Fibrillation in Human Hearts An In Vivo Study

Satish C. Toal, Talha A. Farid, Raja Selvaraj, Vijay S. Chauhan, Stephane Masse, Joan Ivanov, Louise Harris, Eugene Downar, Michael R. Franz, Kumaraswamy Nanthakumar. Circulation: Arrhythmia and Electrophysiology 2009; 2: 562-570

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Background— Action potential duration (APD) variation is an important determinant of wave break and reentry. The determinants of APD variability during early ventricular fibrillation (VF) in myopathic human hearts have not been studied. The objective of this study was to study the role of APD restitution and short-term cardiac memory on variation in human VF. Methods and Results— The study consisted of 7 patients (67±9 years old) with ejection fraction <35%. Monophasic action potentials were recorded from the right and/or left ventricular septum during VF. APD60/90 was measured in sinus beat preceding induction of VF, and its amplitude was used to define 60%/90% repolarization in VF. The monophasic action potential upstroke (dV/dtmax) was used to characterize local excitability. Simple linear regression showed that variability in APDn60 was determined by APD/diastolic interval restitution (R2=0.48, P<0.0001) and short-term memory (APD60 n−1, n−2, n−3, n−4; R2=0.55, 0.40, 0.33, and 0.27 respectively; P<0.001). Using multiple stepwise regression, short-term memory and restitution accounted for 62% of variance in APD60 (P<0.001). Individually, memory effect had the greatest contribution to APD variability (R2=0.55, P<0.0001). Conclusions— In early human VF, short-term memory and APD/diastolic interval restitution explain most of the APD variability, with memory effects predominating. This suggests that in early human VF, short-term cardiac memory may provide a novel therapeutic target to modulate progression of VF in myopathic patients.

99. Re: High amplitude T-wave alternans precedes spontaneous ventricular tachycardia or fibrillation in ICD electrograms

Selvaraj, R.J. and Chauhan, V.S.. Heart Rhythm 2008; 5: e5-6

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100. Atrial tracking with a single ICD lead in the ventricle

Spears, Danna and Selvaraj, Raja and Dhopeswarkar, Rajesh and Nanthakumar, Kumaraswamy. Journal of Cardiovascular Electrophysiology 2008; 19: 440--441

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None

101. Human Ventricular Action Potential Duration Restitution

Selvaraj, Raja J. and Chauhan, Vijay S.. None 2008; 51: 1721--1722

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102. Utility of microvolt T-wave alternans to predict sudden cardiac death in patients with cardiomyopathy

Chauhan, Vijay S. and Selvaraj, Raja J.. Current Opinion in Cardiology 2007; 22: 25--32

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PURPOSE OF REVIEW: Sudden cardiac death remains a major cause of mortality among patients with cardiomyopathy and implantable cardioverter-defibrillator therapy has been shown to improve survival in these patients. Effective use of prophylactic implantable cardioverter-defibrillator therapy requires accurate risk stratification beyond assessment of ejection fraction, however. Repolarization alternans is a harbinger of ventricular arrhythmias and its measurement from body-surface recordings, also known as microvolt T-wave alternans, is emerging as an effective prognostic tool in these patients based on recent clinical trials.$\backslash$n$\backslash$nRECENT FINDINGS: We review the pathogenesis and determinants of repolarization alternans. The current techniques for measuring T-wave alternans from the body surface are compared, including the spectral and modified moving average methods. Recent clinical trials evaluating the prognostic utility of T-wave alternans in patients with ischemic and nonischemic cardiomyopathy and no prior arrhythmic events are summarized. The findings of these studies are discussed in the context of implantable cardioverter-defibrillator prophylaxis. Body-surface T-wave alternans is an evolving technique and its limitations are presented along with approaches to improve its predictive accuracy.$\backslash$n$\backslash$nSUMMARY: Risk stratification with T-wave alternans has the potential to guide prophylactic implantable cardioverter-defibrillator therapy in a growing population of patients with cardiomyopathy.

103. Endocardial and Epicardial Repolarization Alternans in Human Cardiomyopathy. Evidence for Spatiotemporal Heterogeneity and Correlation With Body Surface T-Wave Alternans

Selvaraj, Raja J. and Picton, Peter and Nanthakumar, Kumaraswamy and Mak, Susanna and Chauhan, Vijay S.. Journal of the American College of Cardiology 2007; 49: 338--346

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Objectives: The aim of this study was to define the spatiotemporal distribution of intracardiac alternans and its relationship to body surface alternans in humans. Background: Spatial heterogeneity of alternans exists in the animal heart owing to nonuniform calcium cycling and restitution kinetics. Patients with cardiomyopathy manifest similar myocardial substrate, which might influence the distribution of intracardiac alternans and its projection onto the body surface. Methods: Repolarization alternans was simultaneously measured from unipolar electrograms in the right ventricular endocardium, left ventricular (LV) epicardium, and the surface electrocardiogram in patients with cardiomyopathy (n = 14, LV ejection fraction 29 ± 2{\%}) during atrial pacing at cycle length (CL) 800, 600, and 500 ms. Alternans was determined from the entire JT interval as well as the early, mid, and late JT interval with spectral analysis. Results: Alternans was not uniformly distributed within the heart, with alternating and nonalternating myocardial segments lying adjacent to one another. A greater number of epicardial sites exhibited alternans than endocardial sites at CL 600 ms. Temporal heterogeneity in alternans was present along the JT interval, and apical segments had proportionately less alternans in the late JT interval than mid or basal segments, resulting in apicobasal alternans heterogeneity in late JT interval. Discordant alternans was seen in 5 patients confined to the epicardium. Patients with surface alternans had a greater proportion of intracardiac sites with alternans when compared with those patients without surface alternans. Conclusions: Spatiotemporal heterogeneity and discordant alternans are evident in patients with cardiomyopathy. Greater spatial distribution of intracardiac alternans is associated with measurable body surface alternans. {\textcopyright} 2007 American College of Cardiology Foundation.

104. Letter by Selvaraj and Chauhan regarding article, "upsurge in T-wave alternans and nonalternating repolarization instability precedes spontaneous initiation of ventricular tachyarrhythmias in humans" [1]

Selvaraj, Raja J. and Chauhan, Vijay S.. Circulation 2007; 115: None

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None

105. Steeper restitution slopes across right ventricular endocardium in patients with cardiomyopathy at high risk of ventricular arrhythmias

Selvaraj, R. J. and Picton, P. and Nanthakumar, K. and Chauhan, V. S.. AJP: Heart and Circulatory Physiology 2006; 292: H1262--H1268

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Steep action potential duration (APD) restitution slopes ({\textgreater}1) and spatial APD restitution heterogeneity provide the substrate for ventricular fibrillation in computational models and experimental studies. Their relationship to ventricular arrhythmia vulnerability in human cardiomyopathy has not been defined. Patients with cardiomyopathy [left ventricular (LV) ejection fraction {\textless}40{\%}] and no history of ventricular arrhythmias underwent risk stratification with programmed electrical stimulation or T wave alternans (TWA). Low-risk patients (n = 10) had no inducible ventricular tachycardia (VT) or negative TWA, while high-risk patients (n = 8) had inducible VT or positive TWA. Activation recovery interval (ARI) restitution slopes were measured simultaneously from 10 right ventricular (RV) endocardial sites during an S1-S2 pacing protocol. ARI restitution slope heterogeneity was defined as the coefficient of variation of slopes. Mean ARI restitution slope was significantly steeper in the high-risk group compared with the low-risk group [1.16 (SD 0.31) vs. 0.59 (SD 0.19), P = 0.0002]. The proportion of endocardial recording sites with a slope {\textgreater}1 was significantly larger in the high-risk patients [47{\%} (SD 35) vs. 13{\%} (SD 21), P = 0.022]. Spatial heterogeneity of ARI restitution slopes was similar between the two groups [29{\%} (SD 16) vs. 39{\%} (SD 34), P = 0.48]. There was an inverse linear relationship between the ARI restitution slope and the minimum diastolic interval (P {\textless} 0.001). In cardiomyopathic patients at high risk of ventricular arrhythmias, ARI restitution slopes along the RV endocardium are steeper, but restitution slope heterogeneity is similar compared with those at low risk. Steeper ARI restitution slopes may increase the propensity for ventricular arrhythmias in patients with impaired left ventricular function.

106. Congenital long QT syndrome presenting as epilepsy

Raja Jai Sundar S, Parvathy C. S., Joy M. Thomas and Sudarsana G. Indian Pediatrics 2003; 40: 1201-1203

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None

  • Cited 9 times (Jun 2018)

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