Intensity of murmurs correlates with severity of valvular regurgitation

PURPOSE: To evaluate the relationship between the intensity of murmurs and severity of mitral and aortic regurgitation. PATIENTS AND METHODS: Consecutive patients with chronic isolated aortic (n = 40) or mitral (n = 170) regurgitation undergoing echocardiographic quantitation of regurgitation between 1990 and 1991 were studied. Regurgitant volume and fraction were measured using two simultaneous methods (quantitative Doppler echocardiography and quantitative two-dimensional echocardiography); the intensity of the regurgitant murmur (grade 0 to 6) was noted by physicians unaware of the study. RESULTS: Correlations between murmur intensity and regurgitant volume and fraction were good in aortic regurgitation (r = .60 and r = .67, respectively; P <0.001) and mitral regurgitation (r = .64 and r = .67, respectively; P <0.001) but weaker (r = .47 and r = .45, respectively) in the subset of mitral regurgitation of ischemic or functional cause. Murmur intensity grades ≥3 for aortic regurgitation and ≥4 for mitral regurgitation predicted severe regurgitation (regurgitant fraction ≥40%) in 71% and 91% of patients, respectively. Murmur grades ≤1 for aortic regurgitation and ≤2 for mitral regurgitation predicted 'not severe' regurgitation in 100% and 88% of patients, respectively. Murmur grades 2 for aortic regurgitation and 3 for mitral regurgitation were not correlated to degree of regurgitation. The severity of regurgitation was the most powerful determinant of intensity of murmur. CONCLUSIONS: Murmur intensity correlates well with the degree of chronic organic aortic and mitral regurgitation, and can be used as a predictor of regurgitation severity and as a simple guideline for diagnostic testing in these patients.