Characteristics of a New Repolarization Descriptor Substituted for T-Wave Morphology Analysis in Patients With Cardiomyopathy and Myocardial Infarction

Abstract

Background Total cosine R-to-T (TCRT) is a descriptor of T-wave morphology analysis based on singular value decomposition of 12-lead electrocardiograms (ECGs), which is useful in risk stratification of patients with myocardial infarction (MI). A new marker of standard ECG substituted for TCRT is proposed and the aim of this study was to evaluate the correlation between the new index and TCRT in patients with cardiomyopathy and MI. Methods and Results Patients were divided into 2 groups: patients with cardiomyopathy (group CM, n=21, male =13), and patients with MI (group MI, n=36, male =28). TCRT was calculated using a custom software package. The ventricular gradient (VG)-index was defined as the total number of leads with opposite vectors for the QRS and T-wave. The value of TCRT was significantly lower in group CM than in group MI (-0.50±0.51 vs -0.04±0.65, p<0.01). The value for the VG-index was significantly greater in group CM than in group MI (5.9±3.4 vs 4.2±2.4, p<0.05). There was a significant correlation between TCRT and the VG-index in all of the patients (r²=0.47). Conclusion The VG-index is significantly correlated with TCRT, and both descriptors distinguish patients with MI from those with cardiomyopathy. (Circ J 2006; 70: 1322 - 1326)