title: Characteristics of the electrocardiogram in patients with continuous-flow left ventricular assist devices.
abstract: BACKGROUND
  Electrocardiograms (ECGs) are routinely obtained in patients with advanced congestive heart failure (CHF) before and after surgical implantation with a left-ventricular assist device (LVAD). As the number of patients with CHF is increasing, it is necessary to characterize the changes present in the ECG of patients with LVADs.
  
  
  METHODS
  ECGs of 43 patients pre- and postimplantation of a HeartMate II LVAD were compared to characterize the presence of an LVAD using the following six criteria (LVADS2 ): low limb-lead voltage, ventricular pacing, artifact (electrical), duration of the QRS > 120 milliseconds, ST-elevation in the lateral leads, and splintering of the QRS complex. Additionally, 50 ECGs of non-LVAD patients coded as "lateral myocardial infarction (MI)" and 50 ECGs coded as "ventricular pacing" were chosen at random and scored. Odds ratios were calculated using Fisher's exact test. Logistic regression models were built to predict the presence of an LVAD in all patients.
  
  
  RESULTS
  Univariate analysis of the pre- and post-LVAD ECGs confirmed that all criteria except the "Duration of QRS > 120 milliseconds" characterized the ECG of a patient with an LVAD. Electrical artifact and low limb-lead voltage yielded the greatest association with an LVAD-ECG.
  
  
  CONCLUSIONS
  The ECG of a patient with end-stage CHF significantly changes with LVAD implantation. The LVADS2 criteria provide a framework towards characterizing and establishing a new baseline of the ECG in a patient with a continuous-flow LVAD.
authors.affiliation: Cardiovascular Division, Department of Internal Medicine, School of Medicine, Washington University, Saint Louis, MO.
authors.forename: Sara C
authors.initials: SC
authors.lastname: Martinez
authors.forename: Derrick
authors.initials: D
authors.lastname: Fansler
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Lau
authors.forename: Eric L
authors.initials: EL
authors.lastname: Novak
authors.forename: Susan M
authors.initials: SM
authors.lastname: Joseph
authors.forename: Robert E
authors.initials: RE
authors.lastname: Kleiger
mesh_terms: D004562:Electrocardiography / Q000706:statistics & numerical data*; D005260:Female; D006333:Heart Failure / Q000503:physiopathology* / Q000628:therapy*; D006353:Heart-Assist Devices; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome
keywords: clinical; implantable devices-biventricular pacing/defibrillation; noninvasive techniques-electrocardiography