Ventricular tachyarrhythmia onset in patients with implantable cardioverter defibrillators

Abstract Ventricular tachyarrhythmia (VT) onset is studied by reviewing spontaneous intracardiac electrograms (EGMs) from coronary artery disease (CAD) and dilated cardiomyopathies (DCM) patients with implantable cardioverter-defibrillators (ICD). A total of 165 VT episodes (79 CAD and 86 DCM) from 37 patients (26 CAD and 11 DCM) are analysed. Modes of VT onset are divided into: (i) premature ventricular contraction (PVC); (ii) PVC preceded by a short-long-short cycle (SLS); (Hi) PVC preceded by a pacing beat after a post-ectopic escape interval (PM). VT cycle, median RR cycles of 4 (LastRR4s) and 20 sec (LastRR20s) immediately before VT onset, coupling interval and prematurity index are examined. Significant differences are assessed by Student T-test with p < 5%. DCM patients have more VT episodes and a greater variability of the VT initiation patterns than CAD. We observed, both in DCM and CAD, that PVC onset is the most frequent initiation pattern, while LastRR4s and LastRR20s are significantly higher in PM than PVC or SLS onset. This indicates importance of proper ICD setup on the patients, and it may be useful to predict the risk of experiencing VTs with PM onset of the patients.