Challenges of device therapy for ventricular tachycardia in the rate range of sinus rhythm

A method is described for patient-activated detection of ventricular tachycardia, under circumstances in which automatic algorithms fail. We present a case of a patient with an implanted defibrillator (Jewel PCD) who presented with symptomatic exercise-induced ventricular tachycardia that was only marginally faster than the preceding sinus tachycardia. Programming the sudden onset criterion avoided delivery of therapy into sinus tachycardia, but failed to detect ventricular tachycardia. Brief application of a magnet resulted in successful detection and therapy. This method is device-specific and requires a co-operative, insightful patient. The benefits and risks of such an approach are discussed.