Various patterns of intracardiac electrogram T-wave alternans prior to ventricular tachyarrhythmias in implantable cardioverter-defibrillator patients
Heart Rhythm, 07/05/2012
Ikeda T et al. – The authors indicate different patterns of intracardiac electrogram T–wave alternans (IE–TWA) prior to spontaneous ventricular tachyarrhythmia (VTAs). The phenomena of IE–TWA correspond to outcomes of M–TWA measured during exercise in the surface electrocardiogram.Methods
- The authors analyzed right ventricular ring–can electrogram recordings just prior to VTA episodes and compared T–wave pattern and degree of variation to baseline recordings from 3 patients (2 with idiopathic ventricular fibrillation and 1 with hypertrophic cardiomyopathy) who were enrolled in the Japan Intracardiac Electrogram TWA Study of ICD Recipients.
- In a stable state, the authors measured the M–TWA of the surface electrocardiogram during treadmill exercise in these 3 patients.
- The authors found 3 patterns of IE–TWA among these 3 patients with implantable cardioverter–defibrillator immediately prior to spontaneous VTAs.
- Case 1 had AB pattern of IE–TWA, case 2 ABC pattern, and case 3 nonspecific pattern but great T–wave amplitude variations.
- These IE–TWA amplitudes and the distribution of T–amplitude difference were greater than at baseline.
- Case 1 had a positive outcome in regard to the M–TWA determination, whereas cases 2 and 3 did not.