Role of echocardiography in assessing the mechanism and effect of ramipril on functional mitral regurgitation in dilated cardiomyopathy.

The objectives of this article are to determine the possible mechanism of functional mitral regurgitation in patients with dilated cardiomyopathy (DCM) and to know the effect of ramipril on left ventricle (LV) and mitral regurgitation by ECHO. Several postulates are put forth for functional mitral regurgitation in DCM, and mitral annular dilatation is said to be the primary mechanism in the past, but the exact mechanism is not clear. Though angiotensin converting enzyme (ACE) inhibitors are known to remodel the LV, their beneficial effect in patients with DCM with functional mitral regurgitation is not known. Various cardiac dimensions and degree of mitral regurgitation were measured by echocardiography in 30 normal control group and in 30 patients with DCM of various etiologies except ischemic, before and after ramipril therapy. There was a significant difference in all parameters especially sphericity of left ventricle and position of papillary muscles (P < 0.0003) in DCM patients, but mitral valve annulus did not show significant change (P < 0.3) compared to control group. In 50% of the patients, the functional mitral regurgitation totally disappeared. In 30% of patients, it came down from grade II to I or became trivial. In 20% of patients, it remained unchanged. There was remarkable improvement in sphericity, LV dimension, volumes, and EF%, which increased from 31 +/- 9.81 to 39.3 +/- 8.3% (P < 0.0003). It is concluded that echocardiography clearly demonstrates the increased sphericity of LV in DCM. The lateral migration of papillary muscles possibly plays a major role in functional mitral regurgitation. Ramipril significantly reduces not only sphericity but also functional mitral regurgitation.