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[Prolongation of the averaged QRS complex. A simple prognostic factor in patients with post-infarction bundle branch

B Brembilla-Perrot1, C Suty-Selton, P Houriez

  • 1Service de cardiologie, CHU de Brabois, 54500 Vandoeuvre.

Archives Des Maladies Du Coeur Et Des Vaisseaux
|February 24, 2001
PubMed

Insights

In patients with myocardial infarction and bundle branch block, inducible ventricular tachycardia predicts mortality. Prolonged QRS duration is also a poor prognostic factor but does not specifically predict sudden death.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Internal Medicine

Background:

  • Patients with myocardial infarction and bundle branch block (BBB) experiencing syncope face a high risk of sudden cardiac death.
  • Identifying the cause of syncope in this population is crucial for risk stratification and management.

Purpose of the Study:

  • To evaluate the diagnostic utility of non-invasive tests for syncope in patients with prior myocardial infarction and BBB.
  • To compare non-invasive findings with electrophysiological study (EPS) results.
  • To identify prognostic factors for mortality and sudden death in this high-risk group.

Main Methods:

  • The study included 134 patients (83 with right BBB, 51 with left BBB) with a history of myocardial infarction and syncope.
  • Non-invasive investigations included 24-hour Holter monitoring, high-amplification ECG, and left ventricular ejection fraction measurement.
  • Electrophysiological investigation assessed atrioventricular conduction and inducibility of ventricular tachycardia (VT).

Main Results:

  • 91 patients had inducible sustained VT, and 24 had atrioventricular conduction defects (14 with VT).
  • During follow-up, 12 sudden deaths and 13 cardiac failure deaths occurred.
  • Inducible VT was a significant risk factor for overall mortality and sudden death.
  • Prolonged QRS duration (>165 ms) was an independent risk factor for overall cardiac mortality.

Conclusions:

  • Prolonged QRS duration (>160 ms for RBBB, >170 ms for LBBB) after myocardial infarction with syncope is a significant poor prognostic indicator.
  • While indicative of increased mortality risk, QRS duration is not a specific predictor of sudden death.
  • Electrophysiological assessment, particularly VT inducibility, remains vital for risk stratification.

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