jipmer_logo.png

Persistent VT after revascularization

Raja Selvaraj
Cardiac Electrophysiologist
Professor of Cardiology
JIPMER

Mechanisms of VT in acute MI

  • Ischemia and resultant local electrolyte abnormalities
  • Necrosis and healing, surviving purkinje fibers
  • Reperfusion
  • Electrolyte abnormalities
  • Autonomic changes
  • Mechanical stretch of failing ventricle

AIVR

aivr.jpg

Arrhythmia after CTO PCI

  • 342 patients after CTO PCI
  • VA in 9 (2.6%) patients
  • All were monomorphic VT occurring in median 1 day after PCI
  • Patients with VT were older, had worse LVEF
  • Mortality rates not different between patients with or without VT

König S et al. Incidence and characteristics of ventricular tachycardia in patients after percutaneous coronary revascularization of chronic total occlusions. PLoS One. 2019 Nov 22;14(11):e0225580..

VT after MI

  • GUSTO-1 trial of 40,895 patients who were treated with thrombolytic therapy
  • 3.5 percent developed VT
  • 4.1 percent VF
  • 2.7 percent both VT and VF
  • Approximately 80 to 85 percent of these arrhythmias occurred in the first 48 hours

Newby KH et al. Sustained ventricular arrhythmias in patients receiving thrombolytic therapy: incidence and outcomes. The GUSTO Investigators. Circulation. 1998 Dec 8;98(23):2567-73.

VT after primary PCI

  • 5.7% developed sustained VT / VF
  • 2/3 before end of the procedure
  • 90% within 48 hours

Mehta RH et al. Incidence of and outcomes associated with ventricular tachycardia or fibrillation in patients undergoing primary percutaneous coronary intervention.JAMA. 2009; 301:1779–89.

Early versus late arrhythmias

  • Late VT/VF (> 48 h) associated with higher risk of death (1)
  • VT/VF any time associated with higher risk of death within 90 days (2)
  1. Volpi A et al. One-year prognosis of primary ventricular fibrillation complicating acute myocardial infarction. The GISSI (Gruppo Italiano per lo Studio della Streptochinasi nell’Infarto miocardico) investigators.Am J Cardiol. 1989; 63:1174–8.
  2. Mehta RH et al. Incidence of and outcomes associated with ventricular tachycardia or fibrillation in patients undergoing primary percutaneous coronary intervention.JAMA. 2009; 301:1779–89.

vt_vf_mortality.png

Mehta RH et al. Incidence of and outcomes associated with ventricular tachycardia or fibrillation in patients undergoing primary percutaneous coronary intervention.JAMA. 2009; 301:1779–89.

Management

  • ? Ischemia - Revascularization
  • Correction of electrolyte abnormalities
  • Pharmacological therapy
  • Other measures
  • Ablation
  • ICD

Revascularization

  • Polymorphic VT / VF
  • Other evidence of ischemia

subash_vt.jpg

Electrolyte abnormalities

  • Hypokalemia and hypomagnesemia are common
  • Associated with VA during an acute MI
  • Magnesium should be repleted to facilitate replacement of the potassium

Beta blockers

  • Only antiarrhythmic that improves survival
  • Reduce inotropes
  • Sedation

Huang BT et al. Meta-analysis of relation between oral b-blocker therapy and outcomes in patients with acute myocardial infarction who underwent percutaneous coronary intervention. Am J Cardiol. 2015;115:1529–1538. doi: 10.1016/j.amjcard.2015.02.057

Lidocaine

  • Class Ib
  • May be beneficial (1)
  • May be neutral
  • Mexilitene

Piccini JP et al. Antiarrhythmic drug therapy for sustained ventricular arrhythmias complicating acute myocardial infarction. Crit Care Med. 2011;39:78–83. doi: 10.1097/CCM.0b013e3181fd6ad7.

Amiodarone

  • Safe with structural heart disease
  • Time to take effect

Ranolazine

  • Reduced NSVT
  • No change in other outcomes

Karwatowska-Prokopczuk E et al. The risk of sudden cardiac death in patients with non-ST elevation acute coronary syndrome and prolonged QTc interval: effect of ranolazine. Europace. 2013;15:429–436. doi: 10.1093/europace/eus400

Sedation

  • Reduces sympathetic outflow
  • Deep sedation in VT storm

Sympathetic blockade

  • Stellate ganglion block
  • Thoracic epidural anaesthesia

Bourke T et al. Neuraxial modulation for refractory ventricular arrhythmias: value of thoracic epidural anesthesia and surgical left cardiac sympathetic denervation. Circulation. 2010 Jun 1;121(21):2255-62.

Overdrive pacing

  • Suppress automaticity
  • Induce exit block
  • Terminate / prevent reentry

Ablation

  • 70% success
  • Periprocedural mortality - 3%
  • Long term mortality - 18%
  • Ablate automatic foci, reentry, substrate

Stevenson WG et al. Multicentre Themocool VT Ablation Trial Investigators. Irrigated radiofrequency catheter ablation guided by electroanatomic mapping for recurrent ventricular tachycardia after myocardial infarction: The Multicentre Thermocool Ventricular Tachycardia Ablation Trial. Circulation. 2008;118:2773–2782. doi: 10.1161/CIRCULATIONAHA.108.788604.

Mechanical circulatory support

  • Helps reduce inotrope use
  • Supports procedures
  • IABP, Impella, VA-ECMO

ICD

  • Not in acute phase
  • Secondary prevention for VA after 48 hours

Summary

  • Persistent VT after revascularization in MI uncommon, but difficult problem
  • Most occur early in course
  • Sympathetic blockade is key to management
  • Late arrhythmias indicate high long term risk of sudden death and benefit from ICD