title: Symptomatic and asymptomatic left-ventricular systolic dysfunction in an urban population.
abstract: BACKGROUND
  In most previous epidemiological studies on the prevalence of chronic heart failure (CHF) the disorder has been defined on clinical criteria. In a cross-sectional survey of 2000 men and women aged 25-74, randomly sampled from one geographical area, we assessed left-ventricular systolic function by echocardiography.
  
  
  METHODS
  1640 (83%) of those invited took part. They completed a questionnaire on current medication, history, and symptoms of breathlessness. Blood pressure was measured and electrocardiography (ECG) and echocardiography were done. Left-ventricular ejection fraction was measurable in 1467 (89.5%) participants by the biplane Simpson's rate method.
  
  
  RESULTS
  The mean left-ventricular ejection fraction was 47.3%. The prevalence of definite left-ventricular systolic dysfunction (defined as a left-ventricular ejection fraction < or = 30%) was 2.9% overall (43 participants); it increased with age and was higher in men than in women (4.0 vs 2.0%). The left-ventricular systolic dysfunction was symptomatic in 1.5% of participants and asymptomatic in 1.4%, 83% of participants with left-ventricular systolic dysfunction had evidence of ischaemic heart disease (IHD) from history or ECG criteria compared with 21% of those without this abnormality (p < 0.001). Hypertension was also more common in those with left-ventricular systolic dysfunction (72 vs 38%, p < 0.001), but there was no difference between those with and without left-ventricular systolic dysfunction in the rate of hypertension without IHD.
  
  
  CONCLUSIONS
  Left-ventricular systolic dysfunction was at least twice as common as symptomatic heart failure defined by clinical criteria. The main risk factors are IHD and hypertension in the presence of IHD; screening of such high-risk groups for left-ventricular systolic dysfunction should be considered.
authors.affiliation: Department of Cardiology, Western Infirmary, Glasgow, UK.
authors.forename: T A
authors.initials: TA
authors.lastname: McDonagh
authors.forename: C E
authors.initials: CE
authors.lastname: Morrison
authors.forename: A
authors.initials: A
authors.lastname: Lawrence
authors.forename: I
authors.initials: I
authors.lastname: Ford
authors.forename: H
authors.initials: H
authors.lastname: Tunstall-Pedoe
authors.forename: J J
authors.initials: JJ
authors.lastname: McMurray
authors.forename: H J
authors.initials: HJ
authors.lastname: Dargie
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006333:Heart Failure / Q000453:epidemiology; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000453:epidemiology; D015995:Prevalence; D012307:Risk Factors; D012494:Sampling Studies; D012606:Scotland / Q000453:epidemiology; D013318:Stroke Volume; D014505:Urban Population; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000453:epidemiology*