Abstract 13011: A Swimmer with Ventricular Tachycardia: Multiple Wavelets or a Pebble in a Pond?

A 19-year-old male collegiate swimmer presented with palpitations occurring after severe exertion. He underwent echocardiogram and treadmill stress test which were normal. Event monitor placed immediately after swimming revealed several episodes of fast (220-240 bpm), polymorphic VT separated by 1-2 seconds of sinus rhythm over several minutes. Differential diagnosis included Brugada syndrome, catecholaminergic polymorphic VT (CPVT), arrhythmogenic right ventricular cardiomyopathy (ARVC), and malignant right ventricular outflow tract (RVOT) VT. Cessation of exercise was recommended. Cardiac MRI was normal. Electrophysiology study with high dose isoproterenol induced spontaneous VT that originated with a RVOT premature ventricular complex (PVC) but was pleomorphic and approximated the clinical VT seen on event monitor. No ablation was performed due to the polymorphic nature of the VT. Signal-averaged ECG was abnormal, fulfilling one minor criteria for the diagnosis of ARVC, however no other criteria were p...