Induction of ventricular tachycardia with the fourth extrastimulus and its relationship to risk of arrhythmic events in patients with post-myocardial infarct left ventricular dysfunction

Sarah Zaman, Saurabh Kumar, Arun Narayan, Gopal Sivagangabalan, Aravinda Thiagalingam, David L. Ross, Stuart P. Thomas, Pramesh Kovoor

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16 Citations (Scopus)

Abstract

AimsThe prognostic significance of ventricular tachycardia (VT) induced by three extrastimuli (ES) is similar to that of VT induced by one or two ES in patients with coronary disease and abnormal left ventricular (LV) function. The significance of VT inducible with four ES is unclear. To examine the prognostic significance of VT inducible with the fourth ES in patients with post-myocardial infarct (MI) LV dysfunction.Methods and resultsConsecutive patients (n 432) with post-MI LV ejection fraction ≤40 underwent electrophysiological (EP) studies for risk stratification. Inducible VT < 200 ms cycle length (CL) with one to four ES was considered inducible. The primary endpoint of arrhythmia (sudden death or spontaneous VT/ventricular fibrillation) was compared among patients with VT inducible with less than or equal to two, three, and four ES. The incidence of inducible VT was 37.9 (n 164). In patients with inducible VT, inducibility was with less than or equal to two, three, and four ES in 24 (n 39), 46 (n 75), and 30 (n 50). Compared to VT induced with less than or equal to three ES, VT induced with the fourth ES was of shorter CL (218 vs. 256 ms, P 0.01) and more likely to be haemodynamically unstable requiring cardioversion (77 vs. 55, P 0.05). After 3 years the primary endpoint occurred in 28 ± 8, 28 ± 6, and 18 ± 6 in patients with VT induced with less than or equal to two, three, and four ES, respectively (P 0.31) and in 5 ± 2 of EP-negative patients (P< 0.01).ConclusionIn patients with post-MI LV dysfunction, VT can be induced in a significant proportion of patients with the fourth ES. These patients are at comparable risk of arrhythmia to patients with inducible VT with less than or equal to three ES.

Original languageEnglish
Pages (from-to)1771-1777
Number of pages7
JournalEuropace
Volume14
Issue number12
DOIs
Publication statusPublished - Dec 2012
Externally publishedYes

Keywords

  • Electrophysiology study
  • Implantable cardioverter defibrillator
  • Myocardial infarction
  • Primary prevention
  • Sudden death
  • Ventricular tachycardia

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