Persistent Slow Ventricular Tachycardia following AICD-A Shocking Dilemma!

Implantable Cardioverter and Defibrillators (ICD) prolong lifespan in patients at high risk of tachyarrhythmia, by their ability to appropriately detect and terminate it on the basis of Tachycardia Detection Rate (TDR). However, ICD patients often have Slow ventricular tachycardia (VT) defined as those below the detection limit of ICD. Such Slow VT's are not entirely benign, leading to frequent emergency visits, in-hospital admissions, rate-induced cardiomyopathy and rarely death. Lowering the TDR to detect such arrhythmias has the potential of increasing inappropriate shocks which can be catastrophic. Although such slow VT's are usually terminated by anti-tachycardia pacing, it is not always so. Here, the authors describe two such cases of resistant Slow VT's in post ICD patients which ultimately necessitated ICD shocks.