938 The Prevalence of Early Repolarization in Patients with Noncompaction Cardiomyopathy Presenting with Malignant Ventricular Arrhythmias KADIR CALISKAN, M.D., BARBARA UJVARI, M.D., TAMAS BAUERNFEIND, M.D., DOMINIC A.M.J. THEUNS, Ph.D., RON T. VAN DOMBURG, Ph.D., FERDI AKCA, M.Sc., LUC JORDAENS, M.D., Ph.D., MAARTEN L. SIMOONS, M.D., Ph.D., and TAMAS SZILI-TOROK, M.D., Ph.D. From the Thoraxcenter, Erasmus MC, Rotterdam, the Netherlands Early Repolarization in Noncompaction Cardiomyopathy. Background: Early repolarization (ER) is associated with malignant ventricular arrhythmias, including ventricular fibrillation (VF) and sud- den cardiac death (SCD). One possible mechanism is increased trabeculation with deep intramyocardial invagination, carrying the Purkinje system deeper into the myocardium resulting in delayed depolarization and inhomogenous repolarization. Noncompaction cardiomyopathy (NCCM) is a recently classified, pri- mary cardiomyopathy with excessive trabeculations. In these patients ventricular arrhythmias, including sustained VT and VF, occur frequently. The aim of this study was to determine the prevalence of ER in NCCM patients, especially in those primarily presenting with malignant ventricular arrhythmias or SCD. Methods: We analyzed prospective data from our NCCM registry including 84 patients, median age: 40 (3–79) years. Results: Fourteen patients (17%) initially presented with sustained VT (n = 5) or VF (n = 9) and 70 (83%) with heart failure or else. After the exclusion of 20 patients with the left bundle branch block, 25 (39%) NCCM patients had ER; 3 (6%) located in inferior leads, 14 (27%) in lateral leads, and 8 (15%) in both. None had ER in leads V1 to V3. In those presenting with VT/VF, 9/12 (75%) had ER (2 in inferior leads, 3 in lateral leads and 4 in both), versus 16/52 (31%) in the other patients (P = 0.02). If the NCCM population was dichotomized according to the presence or absence of ER, the long-term outcome for VT/VF appeared worse in the ER positive patients (P = 0.05). Conclusion: There is a high prevalence of ER in NCCM patients, especially in those who present with malignant ventricular arrhythmias. (J Cardiovasc Electrophysiol, Vol. 23, pp. 938-944, September 2012) early repolarization, noncompaction cardiomyopathy, risk factors, sudden cardiac death, ventricular tachycardia, ventricular fibrillation Introduction Early repolarization (ER) and J-point elevation are com- mon in the general population, particularly in healthy young individuals, black males, and athletes. Until recently, these ECG findings were considered benign. 1 In recent years, how- ever, a high prevalence of ER has been reported in athletes experiencing cardiac arrest or sudden death, in patients with in idiopathic ventricular fibrillation (VF) and in patients with a short-QT syndrome. 2-4 Recent data suggest that in particu- lar subjects with a horizontal or descending ST-segment mor- phology are at risk for cardiac arrest, while a rapidly ascend- ing or up sloping ST-segment carry a low risk. 5,6 Increased No disclosures. Address for correspondence: Kadir Caliskan, M.D., Thoraxcenter, Room Bd 577, Erasmus MC, ’s-Gravendijkswal 230, 3015 CE Rotterdam, the Netherlands. E-mail: k.caliskan@erasmusmc.nl Manuscript received 12 December 2011; Revised manuscript received 8 February 2012; Accepted for publication 17 February 2012. doi: 10.1111/j.1540-8167.2012.02325.x left ventricular (LV) trabeculation with deep endomyocardial invagination may be a cause of ER. 3,7 Noncompaction cardiomyopathy (NCCM) is a recently classified, primary cardiomyopathy with excessive trabecu- lation and a strong familial occurrence. 8 The clinical pre- sentation includes congestive heart failure, thrombo-embolic events, supraventricular and ventricular arrhythmias and sudden cardiac death (SCD). 9 The diagnosis relies on morphological findings with cardiac imaging, in particular echocardiography or magnetic resonance imaging (MRI). 10 Malignant ventricular arrhythmias, including sustained ven- tricular tachycardia (VT) and VF, have been reported in 38– 47% and SCD in 13–18% of adult patients with NCCM. 8,9 It should be appreciated that this could be an overestima- tion due to selection bias in tertiary referral centers and that the majority of patients with NCCM presenting with VT/VF have no history of cardiac symptoms or signs. 11 There are little data to predict SCD or malignant arrhythmias in NCCM patients. 12 Given the emerging association of ER with ma- lignant ventricular arrhythmias in different patient popula- tions 2-4 and possible patho-physiological association of ER with increased LV trabeculation (a hallmark of NCCM!), 7 we determined the prevalence, the type and outcome of ER in NCCM, especially in those patients primarily presenting with SCD or malignant ventricular arrhythmias.