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 present. Genetic testing for ARVC and CPVT were normal. Review of the prior studies suggested that all episodes were initiated by a single morphology of RVOT PVC. Repeat electrophysiology study with ablation was performed. One radiofrequency lesion was delivered to the anteroseptum of the RVOT slightly inferior to the pulmonic valve in the area where activation mapping revealed the earliest signal prior to the QRS complex. Despite high dose isoproterenol and aggressive pacing maneuvers, no further VT was inducible. Six consolidative lesions were placed. The patient subsequently was allowed to return to exercise. Malignant RVOT VT is a rare form of RVOT VT, a condition that is typically benign. This case demonstrates that profound impact that curative radiofrequency ablation can have on quality of life and also demonstrates the importance of close scrutiny of the primary clinical data, as the recognition that his polymorphic VT was preceded by a consistent RVOT premature ventricular complex led to successful ablation of this trigger.
- © 2013 by American Heart Association, Inc.