title: Prognostic implications of progressive cardiac conduction disease.
abstract: BACKGROUND
  Progressive cardiac conduction disease (PCCD), characterized by temporal increase in PR interval and QRS duration, may be attributed to diverse pathophysiological mechanisms. This study aimed to investigate whether PCCD is associated with increased risk of cardiovascular morbidity and mortality.
  
  
  RESULTS
  Digital analysis of 12-lead ECG was performed to select patients with PCCD from among a database containing 359,737 ECGs. Long-term prognosis of PCCD was assessed in a large hospital-based population: 458 patients (341 males; mean age, 57.9 ± 14.7 years) with PCCD were enrolled. During a mean follow-up of 13.3 ± 6.4 years, 109 patients were hospitalized for heart failure (HF), and there were 16 and 59 deaths from cardiovascular diseases and all causes, respectively. Multivariate Cox proportional hazards analysis confirmed (1) a significant association of temporal incremental rate of PR interval (≥ 2 ms/year) and QRS duration (≥ 3 ms/year) with HF hospitalization (hazard ratio [HR], 2.34; 95% confidence interval [CI], 1.36-4.05; P=0.002 and HR, 2.08; 95% CI, 1.25-3.53; P=0.01, respectively) and (2) a significant association of temporal incremental rate of PR interval (≥ 4 ms/year) and QRS duration (≥ 5 ms/year) with cardiovascular mortality (HR, 6.9; 95% CI, 1.47-36.96; P=0.02 and HR, 4.31; 95% CI, 1.19-16.5; P=0.03, respectively).
  
  
  CONCLUSIONS
  The severity of PCCD was independently and significantly associated with HF hospitalization and cardiovascular mortality.
authors.affiliation: Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu 520-2192, Japan.
authors.forename: Tamiro
authors.initials: T
authors.lastname: Kawaguchi
authors.forename: Hideki
authors.initials: H
authors.lastname: Hayashi
authors.forename: Akashi
authors.initials: A
authors.lastname: Miyamoto
authors.forename: Tomohide
authors.initials: T
authors.lastname: Yoshino
authors.forename: Atsushi
authors.initials: A
authors.lastname: Taniguchi
authors.forename: Nobu
authors.initials: N
authors.lastname: Naiki
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Sugimoto
authors.forename: Makoto
authors.initials: M
authors.lastname: Ito
authors.forename: Joel Q
authors.initials: JQ
authors.lastname: Xue
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Murakami
authors.forename: Minoru
authors.initials: M
authors.lastname: Horie
mesh_terms: D000328:Adult; D000368:Aged; D000075224:Cardiac Conduction System Disease; D016208:Databases, Factual; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006327:Heart Block / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology; D006333:Heart Failure / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate