Echocardiography in the evaluation of systolic murmurs of unknown cause

PURPOSE: Systolic murmurs are common, and it is important to know whether p hysical examination can reliably determine their cause. Therefore, we prosp ectively assessed the diagnostic accuracy of a cardiac examination in patie nts without previous echocardiography who were referred for evaluation of a systolic murmur. SUBJECTS AND METHODS: In 100 consecutive adults (mean [+/- SD] age of 58 +/ - 22 years) who were referred for a systolic murmur of unknown cause, the d iagnostic accuracy of the cardiac examination by cardiologists (without pro vision of clinical history, electrocardiogram, or chest radiograph) was com pared with the results of echocardiography. RESULTS: The echocardiographic findings included a normal examination (func tional murmur) in 21 patients, aortic stenosis in 29 patients, mitral regur gitation in 30 patients,left or right intraventricular pressure gradient in 11 patients, mitral valve prolapse in 11 patients, ventricular septal defe ct in 4 patients, hypertrophic obstructive cardiomyopathy in 3 patients, an d associated aortic regurgitation in 28 patients. In 28 (35%) of the 79 pat ients with organic heart disease, more than one abnormality was found; comb ined aortic and mitral valve disease was the most frequent combination (n = 22). The sensitivity of the cardiac examination was acceptable for detecti ng ventricular septal defect (100% [4 of 4]), isolated mitral regurgitation (88% [26 of 36]), aortic stenosis (71% [21 of 29]), and a functional murmu r (67% [14 of 21]),but not for intraventricular pressure gradients (18% [2 of 11]), aortic regurgitation (21% [6 of 28]), combined aortic and mitral v alve disease (55% [6 of 11]), and mitral valve prolapse (55% [12 of 22]). I n 6 patients, the degree of aortic stenosis was misjudged on the clinical e xamination, mainly because of a severely diminished left ventricular ejecti on fraction. Significant heart disease was missed completely in only 2 pati ents. CONCLUSION: In adults with a systolic murmur of unknown cause, a functional murmur can usually be distinguished from an organic murmur. However, the a bility of the cardiac examination to assess the exact cause of the murmur i s limited, especially if more than one lesion is present. Thus, echocardiog raphy should be performed in patients with systolic murmurs of unknown caus e who are suspected of having significant heart disease. (C) 2000 by Excerp ta Medica, Inc.