Abstract 13861: Early Repolarization is Associated With an Increasing Occurrence of Life-threatening Ventricular Tachyarrhythmia in Patients With Non-ischemic Heart Disease
Background: Recent studies showed that early repolarization (ER) was associated with higher incidence of ventricular tachyarrhythmia (VT/VF) in patients with idiopathic ventricular fibrillation, Brugada syndrome, and ischemic heart disease. However, it is unknown whether there is an association between ER and VT/VF occurrences in patients with non-ischemic heart disease.
Methods: This study included 102 consecutive patients with non-ischemic heart disease (59±16 years; 72 men) who underwent implantable cardioverter defibrillator (ICD) implantation. The primary endpoint was the occurrence of appropriate device therapy due to VT/VF. We evaluated the presence of ER from the ECG recorded before ICD implantation. ER was electrocardiographically defined as an elevation of the terminal portion of QTS complex of >0.1mV from baseline in at least 2 inferior or lateral leads.
Results: Underlying heart disease were dilated cardiomyopathy in 40, hypertrophic cardiomyopathy in 36, arrhythmogenic right ventricular cardiomyopathy in 9, cardiac sarcoidosis in 5, valvular heart disease in 3, congenital heart disease in 3, and others in the remaining 6 patients. After a median follow-up of 18.0 months (interquartile range, 5.3 to 41.8 months), 34 patients had experienced an episode of appropriate device therapy. ER was found in 12 (35%) of the patients with appropriate device therapy, which was more prevalent than in those without (5%; p<0.001). A multivariate Cox regression analysis revealed that ER (hazard ratio, 5.31; 95% confidence interval, 2.52-11.89; p<0.001) was independent predictor for the occurrence of appropriate device therapy in patients with non-ischemic heart disease. As features of the ER pattern, ER in inferior leads, high amplitude of J-point, notched ER, and ER without ST-junction elevation, all were significantly associated with the occurrence of appropriate device therapy. Subgroup analyses showed that ER was associated with increasing risk of appropriate device therapy in patients with either dilated cardiomyopathy (31% versus 0%; p<0.01) or hypertrophic cardiomyopathy (45% versus 4%; p<0.01).
Conclusion: The presence of ER increases the risk for occurrence of life-threatening VT/VF in patients with non-ischemic heart disease.
- © 2013 by American Heart Association, Inc.