Detection of T-Wave Beat-By-Beat Variations prior to Ventricular Arrhythmias Onset in ICD-Stored Intracardiac Electrograms: The Endocardial T-Wave Alternans Study (ETWAS)

The aim of the Endocardial T-Wave Alternans Study was to prospectively assess the presence of T-wave alternans (TWA) or beat-to-beat repolarization changes on implantable cardioverter-defibrillator (ICD)-stored electrograms (EGMs) immediately preceding the onset of spontaneous ventricular tachycardia (VT) or fibrillation (VF).