Abstract 12999: Different Response to Exercise Testing between Andersen-Tawil Syndrome and Catecholaminergic Polymorphic Ventricular Tachycardia
Introduction:Andersen-Tawil Syndrome (ATS) and catecholaminergic polymorphic ventricular tachycardia (CPVT) are both inherited arrhythmic disorders characterized by bigeminy of premature ventricular contractions (PVCs), and bidirectional and/or polymorphic ventricular tachycardia (VT). This compared clinical characteristics and influence of sympathetic stimulation on ventricular arrhythmias between ATS and CPVT patients.
Methods:The study population included 13 ATS patients with KCNJ2 mutations (11 families, 10 females, 19±11 y.o.) and 7 CPVT patients with hRyR2 mutations (6 families, 3 females, 23±18 y.o.). We compared clinical and electrocardiographic characteristics at baseline and responses of ventricular arrhythmias to treadmill exercise testing between the 2 groups.
Results:No significant differences were observed in age at first cardiac event (ATS vs. CPVT; 11±9 vs. 14±9 y.o.), aborted cardiac arrest (1/13 vs. 2/7), and family history of sudden death (none in both groups). Previous syncopal episodes were more frequently observed in CPVT patients (5/13 vs. 7/7; p=0.01). ATS patients had higher U wave amplitude in V3 (1.9±0.7 vs. 0.9±0.2 mV; p=0.003) and more frequent PVCs (37±38 vs. 0 bpm; p=0.02) at baseline ECG than CPVT patients. Bidirectional or non-sustained polymorphic VTs were induced during exercise in all 7 CPVT patients, although no PVC/VTs were observed before exercise. In contrast, multiple PVC/VTs were observed in 12/13 ATS patients before exercise (PVC bigeminy in 7, bidirectional VT in 6 patients), however, they all disappeared at peak exercise in 11/13 ATS patients and decreased in 2/13 patients.
Conclusions:Responses of ventricular arrhythmias to exercise were totally opposite between patients with ATS and CPVT, which may improve clinical differential diagnosis of ATS and CPVT.
- © 2012 by American Heart Association, Inc.