We assessed the value of symptoms, past history, medications and signs in the evaluation of patients who might have heart failure secondary to left ventricular systolic dysfunction. An open-access echocardiography service was set up to help identify patients with left ventricular systolic dysfunction who might benefit from treatment with an angiotensin-converting-enzyme inhibitor. History and examination were recorded for each of these patients. The patients were divided into groups according to whether left ventricular systolic function was preserved or not and whether various clinical features were present or not. Of 259 consecutive patients studied, 41 had impairment of left ventricular systolic function as assessed by echocardiography. Past history of myocardial infarction and displaced apex beat were the best single predictors of left ventricular systolic dysfunction as assessed by echocardiography. The combination of past history of myocardial infarction and displaced apex had the best positive predictive value of all. Patients with such clinical features or combinations of clinical features may not need echocardiography, and where access to this resource is limited, it could be reserved for patients without such diagnostic features.