title: 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.
  
  
  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 (r(2)=0.47).
  
  
  CONCLUSIONS
  The VG-index is significantly correlated with TCRT, and both descriptors distinguish patients with MI from those with cardiomyopathy.
authors.affiliation: Nippon Medical School, First Department of Internal Medicine, Sendagi, Tokyo, Japan. takuyawo@nms.ac.jp
authors.forename: Takuya
authors.initials: T
authors.lastname: Ono
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Saitoh
authors.forename: Shioto
authors.initials: S
authors.lastname: Itakura
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Tateoka
authors.forename: Isuzu
authors.initials: I
authors.lastname: Ono
authors.forename: Katerina
authors.initials: K
authors.lastname: Hnatkova
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Morimasa
authors.initials: M
authors.lastname: Takayama
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Atarashi
authors.forename: Takao
authors.initials: T
authors.lastname: Katoh
authors.forename: Teruo
authors.initials: T
authors.lastname: Takano
authors.forename: Marek
authors.initials: M
authors.lastname: Malik
mesh_terms: D000328:Adult; D000368:Aged; D009202:Cardiomyopathies / Q000175:diagnosis*; D003937:Diagnosis, Differential; D004562:Electrocardiography / Q000379:methods* / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis*; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012984:Software