Abstract 12166: Prevalence and Outcomes of Concealed Cardiomyopathies in Athletes with Ventricular Arrhythmias and a Structurally Normal Heart
Introduction. Trained athletes may have ventricular arrhythmias (VAs) without evidence of structural cardiac disease. Electroanatomic mapping (EAM) reliably identifies low-voltage areas corresponding to different cardiomyopathic substrates in patients with VAs. Through EAM with EAM-guided biopsy, we assessed the prevalence and prognostic significance of concealed cardiomyopathies in athletes with VAs and a structurally normal heart at non-invasive evaluation.
Methods. From January 2008 to February 2009 we examined 1644 consecutive athletes at our Institution, a national-level referral center for Sports Cardiology. All athletes with repetitive (non-sustained and sustained ventricular tachycardia [VT]) VAs or frequent premature ventricular contractions (PVCs) (>1000/24h) underwent a complete non-invasive evaluation (ECG, signal-averaged ECG, 2D echocardiography, and gadolinium contrast-enhanced cardiac MRI). EAM with EAM-guided biopsy was performed when non-invasive evaluation showed a structurally normal heart.
Results. Repetitive VAs were present in 27 (1.6%) subjects, while frequent PVCs were found in 30 (2.1%). Non-invasive evaluation was normal in 17 athletes. Of these, 13 (76%) ultimately proved to have cardiomyopathies at EAM with EAM-guided biopsy (5 arrhythmogenic right ventricular cardiomyopathy [ARVC], 7 myocarditis, and 1 contraction band necrosis due to undetected caffeine and ephedrine abuse). 3/5 patients with ARVC had an ICD implanted for reproducible induction of hemodynamically unstable VT at electrophysiologic testing; 1 of these had an appropriate ICD shock on rapid sustained VT 13 months after ICD implantation. Two patients with myocarditis and the one with contraction band necrosis underwent catheter ablation of drug-refractory sustained VT after a mean follow-up of 9 ± 2 months from the initial diagnosis.
Conclusions. VAs in apparently healthy athletes often represent the initial expression of underlying cardiomyopathies, and EAM with EAM-guided biopsy increases the diagnostic yield of non-invasive evaluation, including cardiac MRI. Continued clinical surveillance may be warranted in these patients.
- © 2011 by American Heart Association, Inc.