Microvolt T-wave alternans and electrophysiologic testing predict distinct arrhythmia substrates: Implications for identifying patients at risk for sudden cardiac death

BACKGROUND: Better risk stratification of patients receiving an implantable cardioverter-defibrillator (ICD) for primary prevention of sudden cardiac death (SCD) is needed. Although microvolt T-wave alternans (MTWA) and electrophysiologic study (EPS) are independent markers for SCD, the Alternans Before Cardioverter Defibrillator (ABCD) trial found the combination to be more predictive than either test alone. OBJECTIVE: The purpose of this …