Electrocardiographic abnormalities of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a genetic disease characterized by the hypertrophy (thickening) of heart ventricles, and the first cause of sudden cardiac death in the young adults. The ECG is altered in the majority of patients with HCM as a consequence of structural and electrophysiological abnormalities although reliable risk markers are still not available. Fifty four 12-lead Holter recordings (32 HCM patients and 22 controls) have been analyzed in order to obtain specific ECG based biomarkers able to distinguish between both groups. Results showed higher values for HCM in QRS-duration, QT interval (QTc), T peak to T end interval corrected (Tpe) and DRest quantifying dispersion of restitution. Also, morphological features such as ST level, T and QRS amplitudes and energies and the first four Karhunen-Loeve transform (KLT) coefficients were analysed. Results showed statistically significant differences between HCM patients and controls (p-value<0.02) in the QTc interval, ST level, energies and the first and third KLT coefficients. DRest showed higher values in HCM patients (0.08 versus 0.05 in controls) in agreement with in vivo studies suggesting a correlation between increased dispersion and arrhythmic risk.