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

Curr Opin Cardiol. 2007 Jan;22(1):25-32. doi: 10.1097/HCO.0b013e328011aa49.

Abstract

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.

Recent 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.

Summary: Risk stratification with T-wave alternans has the potential to guide prophylactic implantable cardioverter-defibrillator therapy in a growing population of patients with cardiomyopathy.

Publication types

  • Review

MeSH terms

  • Arrhythmias, Cardiac / complications
  • Arrhythmias, Cardiac / mortality
  • Cardiac Pacing, Artificial / methods
  • Cardiomyopathies / physiopathology
  • Cardiomyopathies / therapy*
  • Death, Sudden, Cardiac / etiology
  • Death, Sudden, Cardiac / prevention & control*
  • Defibrillators, Implantable
  • Electrocardiography / methods*
  • Humans
  • Predictive Value of Tests
  • Prognosis
  • Risk Assessment
  • Stroke Volume / physiology
  • Ventricular Fibrillation / diagnosis*
  • Ventricular Fibrillation / etiology
  • Ventricular Fibrillation / prevention & control