title: Atrioventricular block in the postoperative period of heart valve surgery: incidence, risk factors and hospital evolution.
abstract: BACKGROUND
  Disturbances of the cardiac conduction system are potential complications after cardiac valve surgery.
  
  
  OBJECTIVE
  This study was designed to investigate the association between perioperative factors and atrio-ventricular block, the need for temporary cardiac artificial pacing and, if necessary, permanent pacemaker implantation after cardiac valve surgery.
  
  
  METHODS
  Retrospective analysis of the Cardiac Surgery Database - Hospital São Lucas/PUCRS. The data are collected prospectively and analyzed retrospectively.
  
  
  RESULTS
  Between January 1996 and December 2008 were included 1102 valve surgical procedures: 718 aortic valves (65.2%), 407 (36.9%) mitral valve and 190 (17.2%) coronar artery bypass grafting combined with valve repair and 23 (2.1%) aortic and mitral combined surgery. 187 patients (17%) showed clinical and electrocardiographic pattern of atrio-ventricular block requiring artificial temporary pacing. Of these, 14 patients (7.5%) required permanent pacemaker implantation (1.27% of the total valve surgery patients). Multivariate analysis showed association of the incidence of atrio-ventricular block and temporary pacing with mitral valve surgery (OR 1,76; CI 95% 1.08-2.37; P = 0.002), implantation of bioprosthetic devices (OR 1.59; CI 95% 1.02-3.91; P = 0,039), age over 60 years (OR 1.99; CI 95% 1.352.85; P < 0.001), prior use of anti-arrhythmic drugs (OR 1.86; CI 95% 1.04-3.14; P = 0.026) and previous use of b-blocker (OR 1.76; CI 95% 1.25-2.54; P = 0.002). Remarkably the presence of atrio-ventricular block did not significantly show association with increased mortality, but significantly prolonged (P < 0.0001) hospital length-of-stay and, therefore, hospital costs.
  
  
  CONCLUSIONS
  Our study presents a group of predictive factors referring to a specific patient profile by which high risk of atrio-ventricular block and the need of temporary cardiac pacing after cardiac valve surgery it is determined.
authors.affiliation: tHospital São Lucas da Pontificia Universidade Catolica do Rio Grande do Sul,Porto Alegre, Brazil. andredileoni@terra.com.br
authors.forename: Andres Di Leoni
authors.initials: AD
authors.lastname: Ferrari
authors.forename: Carolina Pelzer
authors.initials: CP
authors.lastname: Süssenbach
authors.forename: João Carlos Vieira da Costa
authors.initials: JC
authors.lastname: Guaragna
authors.forename: Jacqueline da Costa Escobar
authors.initials: Jda C
authors.lastname: Piccoli
authors.forename: Guilherme Ferreira
authors.initials: GF
authors.lastname: Gazzoni
authors.forename: Débora Klein
authors.initials: DK
authors.lastname: Ferreira
authors.forename: Luciano Cabral
authors.initials: LC
authors.lastname: Albuquerque
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: Goldani
mesh_terms: D000368:Aged; D001021:Aortic Valve / Q000601:surgery*; D054537:Atrioventricular Block / Q000453:epidemiology* / Q000209:etiology; D002304:Cardiac Pacing, Artificial / Q000706:statistics & numerical data*; D001026:Coronary Artery Bypass / Q000009:adverse effects* / Q000379:methods; D004812:Epidemiologic Methods; D005260:Female; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects* / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery*; D019990:Perioperative Care