title: Electrocardiographic comparison of ventricular premature complexes during exercise test in patients with CPVT and healthy subjects.
abstract: BACKGROUND
  Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare but highly malignant inherited arrhythmic disorder. Although a standardized exercise stress test (ST) is the most reliable way to diagnose CPVT, in 30% only single ventricular premature beats (VPCs) were recorded.
  
  
  OBJECTIVE
  To evaluate whether electrocardiographic characteristics of VPCs during ST distinguish patients with CPVT from healthy subjects.
  
  
  METHODS
  Electrocardiographic characteristics of VPCs during ST in 16 calsequestrin-2 (CASQ2) mutation carriers CPVT patients were compared with that in 36 healthy subjects.
  
  
  RESULTS
  CPVT patients had more VPCs (31 ± 14 vs 3 ± 4, P < 0.0001), longer QRS duration (139 ± 18 ms vs 121 ± 21, P = 0.004), and coupling interval (CI; 476 ± 58 ms vs 355 ± 61 ms, P < 0.0001). The most sensitive characteristics for CPVT were >10 VPCs/test (100% sensitivity, 100% negative predictive value [NPV]), left bundle branch block (LBBB) pattern with inferior axis (88% sensitivity, 94% NPV), and CI longer than 400 ms (88% sensitivity, 94% NPV). Bigeminy or trigeminy or LBBB pattern with inferior axis was most specific for CPVT at 100% (100% positive predictive value PPV, 92% NPV). First VPC during the recovery period and VPC recording more than 1 minute during the recovery period were most specific for healthy subjects (100% specificity, 100% PPV). In multivariate analysis, QRS duration >120 ms (odds ratio 4.2, 95% confidence interval 1-17.6, P = 0.04) and first VPC at ≥10 mets (odds ratio 9.1, 95% confidence interval 2.01-41.1, P = 0.004) each predicted the presence of CPVT.
  
  
  CONCLUSIONS
  Several electrocardiographic criteria can help distinguish VPCs originating from CPVT compared with healthy subjects.
authors: Division of Pacing and Electrophysiology, Rambam Health Care Campus and Bruce Rappaport Faculty of Medicine, Haifa, Israel.
authors: Miry
authors: M
authors: Blich
authors: Ibrahim
authors: I
authors: Marai
authors: Mahmoud
authors: M
authors: Suleiman
authors: Avraham
authors: A
authors: Lorber
authors: Lior
authors: L
authors: Gepstein
authors: Monther
authors: M
authors: Boulous
authors: Asaad
authors: A
authors: Khoury
mesh_terms: D000293:Adolescent; D002155:Calsequestrin / Q000235:genetics; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D012680:Sensitivity and Specificity; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000235:genetics / Q000503:physiopathology; D018879:Ventricular Premature Complexes / Q000175:diagnosis* / Q000235:genetics / Q000503:physiopathology; D000098850:Polymorphic Catecholaminergic Ventricular Tachycardia
chemical_list: C443109:CASQ2 protein, human; D002155:Calsequestrin
keywords: clinical trials; electrophysiology - clinical