Mapping and Ablation of Flutters in Idiopathic Right Atrial Scar

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Raja Selvaraj MD DNB FCE (Toronto)
Cardiac Electrophysiologist
Professor of Cardiology
JIPMER

Case

  • 80 year old male
  • Paroxysmal palpitations
  • Documented tachycardia suggestive of flutter
  • Not responding to drugs
  • Recurrent episodes after previous cavotricuspid isthmus ablation

Catheters

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EP study

  • Rhythm Sinus , PR 160 ms , CL 722 ms , AH 76 ms , HV 65 ms
  • No AP, No dual AV nodal physiology
  • AVWB 560 ms

CS pacing - Is there isthmus conduction ?

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Tachycardia

  • Easily induced with atrial burst pacing or single extrastimulus
  • CL 610 ms, 1:1 AV
  • CS proximal to distal
  • Lateral RA - Craniocaudal

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Selvaraj RJ et al. Chasing red herrings: making sense of the colors while mapping. Circ Arrhythm Electrophysiol. 2014 Jun;7(3):553-6.

Voltage map in sinus rhythm

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Activation map

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Potential circuits

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Entrainment

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PPI - TCL

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Propagation map

Activation map - Where to ablate

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Ablation

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Idiopathic RA scar

  • Five patients
  • 49 - 80 years
  • Persistent (4/5) or paroxysmal macroreentrant AT
  • T-CMP in one patient

EPS / Ablation

  • Single circuit (3/5) or multiple circuits
  • Scar in lateral RA between SVC and IVC
  • All required isthmus ablation, 3/5 needed additional ablation in lateral RA

Substrate and ablation

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  1. Stevenson IH … Kalman JM. Scar-related right atrial macroreentrant tachycardia in patients without prior atrial surgery: electroanatomic characterization and ablation outcome. Heart Rhythm. 2005 Jun;2(6):594-601.
  2. Wieczorek M, Hoeltgen R. Right atrial tachycardias related to regions of low-voltage myocardium in patients without prior cardiac surgery: catheter ablation and follow-up results. Europace. 2013 Nov;15(11):1642-50.
  3. Hygriv B Rao, AK Sivaprasad. Idiopathic Right Atrial Scar. Images in Electrophysiology. Indian Pacing and Electrophysiology Journal 2014;14(1):60-62

Caution - Phrenic nerve

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Summary

  • Right atrial scar in absence of previous surgery or valvular disease is a rare entity
  • Stereotypical pattern of scarring in linear fashion from SVC to IVC
  • "Gaps" in the scar or between scar and SVC / IVC form isthmus for macroreentry
  • Cavotricuspid isthmus remains important for reentry
  • With unmappable flutters, substrate map and ablation of potentials isthmuses is effective
  • Confirm block across line, avoid phrenic nerve

Thanks to

  • J. Balachander
  • Santhosh Satheesh
  • Ajith Ananthakrishna Pillai
  • Avinash
  • Joseph Theodore
  • Sakthivel
  • Ashish Jain
  • Post Doctoral Fellowship at JIPMER - 2 yrs, every June
  • EP 101 - ep101.in