High prevalence of clinically silent severe mitral regurgitation in patients with heart failure: role for echocardiography.

Mitral regurgitation (MR) is common in patients with congestive heart failure (CHF) and has adverse effects on prognosis. In view of the altered hemodynamics in CHF, we examined the accuracy of auscultation for its detection in CHF with reduced systolic function. We examined 370 patients on stable heart failure therapy enrolled in our CHF clinic, if they had a physical examination by one of the two senior cardiologists and an echocardiogram within 2 weeks after the physical examination. The MR murmur was graded 0 to 6 on physical examination. MR was graded 0 to 4 on echocardiography using standard echocardiographic criteria. The left ventricular (LV) ejection fraction was 21 +/- 12% and age was 65 +/- 15 years. By echocardiography MR was present in 345 patients (94%), being 1+ in 162 (44%), 2+ in 80 (22%), 3+ in 54 (15%), and 4+ in 51 (14%). The frequency of an audible MR murmur by physical examination was 4% in 1+ MR, 11% in 2+ MR, 13% in 3+ MR, and 37% in 4+ MR. The audibility of MR murmur was not related to age, sex, body size, LV size, ejection fraction, or left atrial size. In conclusion, grade 3 or 4+ MR is present in one third of patients with CHF and reduced ejection fraction, and is inaudible in three quarters of them by physical examination. Echocardiography is needed for its detection. Audibility of MR murmur cannot be predicted by body size, LV size, or LV function in these patients.