title: Insights into the importance of the electrocardiogram in patients with acute heart failure.
abstract: Patients presenting to the emergency department (ED) with acute heart failure (AHF) are at an increased risk of morbidity and mortality. The electrocardiogram (ECG) is a routine investigation in patients with AHF used to identify potential causes and/or complications. It is unclear whether 12-lead ECG characteristics can serve as a prognostic indicator in this population.
  
  
  
  Patients with AHF from four hospital EDs were prospectively enrolled into the AHF - Emergency Management cohort. In addition to baseline data collection, the first available ECG was read in a core laboratory. Clinical outcomes (all-cause mortality and readmission) were recorded and risk models were developed. Of 937 enrolled patients, 816 had a diagnosis of AHF and an available ECG. Median age of the population was 77 [interquartile range (IQR) 67-85], 47% were female and median ejection fraction was 45% (IQR 30-55). Abnormalities were common, with only 7.5% of patients having a normal ECG. During the median follow-up of 25.7 months, there were 379 (46%) all-cause deaths and 328 (40%) hospital readmissions. Sinus rhythm was associated with better outcomes [hazard ratio (HR) 0.76; 95% confidence interval (CI) 0.62, 0.94], while paced rhythms (HR 1.51, 95% CI 1.11, 2.05), a wide QRS (HR 1.29, 95% CI 1.04, 1.59) and an ECG with any abnormality (HR 1.57, 95% CI 1.01, 2.44) was associated with poorer outcomes. Other individual ECG characteristics were not related to clinical outcomes after risk adjustment.
  
  
  
  Certain ECG abnormalities are common in patients with AHF and associated with poor outcomes. Used in conjunction with other clinical variables, the ECG may be a useful tool in long-term risk stratifying patients.
authors.affiliation: Canadian VIGOUR Centre, University of Alberta in Edmonton, Canada.
authors.forename: Pishoy
authors.initials: P
authors.lastname: Gouda
authors.affiliation: Canadian VIGOUR Centre, University of Alberta in Edmonton, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: Brown
authors.affiliation: Department of Emergency Medicine and School of Public Health, University of Alberta in Edmonton, Canada.
authors.forename: Brian H
authors.initials: BH
authors.lastname: Rowe
authors.affiliation: Canadian VIGOUR Centre, University of Alberta in Edmonton, Canada.|Patient Health Outcomes Research and Clinical Effectiveness Unit, University of Alberta in Edmonton, Canada.|Division of General Internal Medicine, University of Alberta in Edmonton, Canada.
authors.forename: Finlay A
authors.initials: FA
authors.lastname: McAlister
authors.affiliation: Canadian VIGOUR Centre, University of Alberta in Edmonton, Canada.|Division of Cardiology, University of Alberta in Edmonton, Canada.
authors.forename: Justin A
authors.initials: JA
authors.lastname: Ezekowitz
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D002037:Bundle-Branch Block / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D004562:Electrocardiography; D004636:Emergency Service, Hospital; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality; D010359:Patient Readmission / Q000706:statistics & numerical data*; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D013318:Stroke Volume
keywords: Arrhythmias; Cardiology; Electrocardiology; Heart failure