title: [Correlation of Tp-e interval and Tp-e/Q-T ratio with malignant ventricular arrhythmia in patients with implantable cardioverter-defibrillator for primary prevention].
abstract: OBJECTIVE
  To investigate whether Tpeak-Tend interval (Tp-e) and Tp-e/QT ratio are associated with malignant ventricular arrhythmia in patients with implantable cardioverter-defibrillator (ICD) for primary prevention.
  
  
  METHODS
  A cohort of 68 consecutive patients with chronic heart failure undergoing standard ICD for primary prevention indications (NYHA function class II-III, left ventricular ejection fraction ≤35%, systolic cardiomyopathy without prior malignant ventricular arrhythmia) were enrolled in this study. The patients were followed up for 18-48 months and were divided into high-risk group and low-risk group according to the occurrence of the endpoint events of sudden cardiac death (SCD), ventricular tachycardia (VT), or ventricular fibrillation (VF). Electrocardiographic and echocardiographic characteristics, Tp-e, and Tp-e/QT ratio were analyzed in all cases before ICD implantation.
  
  
  RESULTS
  During the follow-up, ICD shock for sustained ventricular tachycardia or ventricular fibrillation occurred in 11 patients; nonsustained ventricular tachycardia (NSVT) that did not require therapy was detected by ICD in 7 patients (high-risk group, 18 cases). ICD did not detect ventricular tachycardia or ventricular fibrillation in 50 patients (low-rsk group). Compared with the low-rsik group, the high-risk group had an increased Tp-e/QT ratio (0.27±0.04 vs 0.22±0.05 P<0.01) and an increased Tp-e (105±15 vs 90±17 ms P<0.01). ROC analysis revealed that a Tp-e/QT ratio ≥0.255 had a sensitivity of 72.2% and a specificity of 65.9%, and a Tp-e ≥103 ms had a sensitivity of 66.7% and a specificity of 67.9% for predicting VT and VF in these patients.
  
  
  CONCLUSIONS
  Increased Tp-e and Tp-e/QT ratio are associated with increased risks of ventricular arrhythmias in patients with ICD for primary prevention.
authors.affiliation: Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.E-mail: 13268265198@163.com.
authors.forename: Ting-Yan
authors.initials: TY
authors.lastname: Zhu
authors.forename: Shu-En
authors.initials: SE
authors.lastname: Teng
authors.forename: Yan-Yu
authors.initials: YY
authors.lastname: Chen
authors.forename: Shen-Rong
authors.initials: SR
authors.lastname: Liu
authors.forename: Su-Rong
authors.initials: SR
authors.lastname: Meng
authors.forename: Jian
authors.initials: J
authors.lastname: Peng
mesh_terms: D016757:Death, Sudden, Cardiac / Q000517:prevention & control*; D017147:Defibrillators, Implantable; D004562:Electrocardiography; D006333:Heart Failure / Q000628:therapy*; D006801:Humans; D011322:Primary Prevention; D012372:ROC Curve; D017180:Tachycardia, Ventricular / Q000517:prevention & control*; D014693:Ventricular Fibrillation; D016277:Ventricular Function, Left