SYMPTOMATIC AND ASYMPTOMATIC LEFT-VENTRICULAR SYSTOLIC DYSFUNCTION INAN URBAN-POPULATION

Background In most previous epidemiological studies on the prevalence of chronic heart failure (CHF) the disorder has been defined on clinic al criteria. In a cross-sectional survey of 2000 men and women aged 25 -74, randomly sampled from one geographical area, we assessed left-ven tricular systolic function by echocardiography. Methods 1640 (83%) of those invited took part. They completed a questionnaire on current med ication, history, and symptoms of breathlessness. Blood pressure was m easured and electrocardiography (ECG) and echocardiography were done. Left-ventricular ejection fraction was measurable in 1467 (89.5%) part icipants by the biplane Simpson's rate method. Findings The mean left- ventricular ejection fraction was 47.3%. The prevalence of definite le ft-ventricular systolic dysfunction (defined as a left-ventricular eje ction fraction less than or equal to 30%) was 2.9% overall (43 partici pants); it increased with age and was higher in men than in women (4.0 vs 2.0%). The left-ventricular systolic dysfunction was symptomatic i n 1.5% of participants and asymptomatic in 1.4%. 83% of participants w ith left-ventricular systolic dysfunction had evidence of ischaemic he art disease (IHD) from history or ECG criteria compared with 21% of th ose without this abnormality (p<0.001). Hypertension was also more com mon in those with left-ventricular systolic dysfunction (72 vs 38%, p< 0.001), but there was no difference between those with and without lef t-ventricular systolic dysfunction in the rate of hypertension without IHD. Interpretation Left-ventricular systolic dysfunction was at leas t twice as common as symptomatic heart failure defined by clinical cri teria. The main risk factors are IHD and hypertension in the presence of IHD; screening of such high-risk groups for left-ventricular systol ic dysfunction should be considered.