Contribuiton of M-mode echocardiography to cardiac diagnosis. An assessment in 1,000 successive patients.

The contribution of M-mode echocardiography to cardiac diagnosis was evaluated in a series of 1,000 successive patients. Among subjects in whom a presumptive clinical diagnosis had been made, echocardiography demonstrated totally unexpected findings in 10 per cent, supported the clinical diagnosis in 50 per cent and was entirely within normal limits in 19 per cent. Among patients with evidence of heart disease but no firm clinical diagnosis, echocardiography established the diagnosis in 23 per cent, including 20 per cent of all patients referred for evaluation of chest pain or arrhythmia of unclear etiology. "Missed" clinical diagnosis frequently involved patients with mitral valve prolapse, congestive cardiomyopathy, pericardial disease or asymmetrical septal hypertrophy of the heart. This study quantifies the amount of independent information contributed by echocardiography to cardiac diagnosis and demonstrates that this technic provides data of important clinical relevance in a surprisingly large number of cardiac patients.