Implications of "slower" ventricular tachycardia on clinical management and detection and therapy function of implantable cardioverter defibrillators.

Sophisticated dual-chamber atrioventricular and rate-responsive pacing therapies, cardiac resynchronization therapy (CRT), detection and therapies for ventricular tachycardia and fibrillation (VT/VF) form some major components of multitask functions of current implantable cardioverter defibrillators (ICDs). Appropriate programming of these devices is necessary for them to perform all such tasks precisely. In this report, we describe a case of a patient with Chagas cardiomyopathy with marked cardiomegaly, scarred ventricles, prior epicardial and endocardial ablations and on antiarrhythmic pharmacotherapy for VT, who presented with symptomatic wide complex tachycardia at a slower rate than definition of VT, and in whom programming for detection and therapy for "slow" VT could not be performed due to default technological limitation of the CRT-D.