Apex cardiogram in patients with prolapsing mitral valve

Abstract

The characteristics of the apex cardiogram in patients with a prolapsing mitral valve were investigated. Twenty-four patients having typical echocardiographic evidence of prolapsing mitral leaflets and midsystolic clicks (with or without apical systolic murmurs) were studied. Of the 24 patients, 16 (67 percent) had a sharp systolic retraction on the apex cardiogram occurring simultaneously with the systolic click. Sharp systolic retractions were not observed on the apex cardiogram of normal subjects or patients with rheumatic mitral insufficiency. Eight of the 16 patients had either no or a small systolic retraction at rest, but the systolic retraction was elicited or accentuated by standing or inhalation of amyl nitrite. In patients with the sharp systolic retraction at rest, the click and the systolic retraction occurred earlier in systole during standing or inhalation of amyl nitrite. In 12 patients prolapsing mitral valves were confirmed by left ventricular cineangiograms. Sharp systolic retractions were present in the apex cardiograms in eight of these patients; seven of the eight had moderate to severe prolapse of both mitral leaflets. In the four remaining patients who underwent catheterization no sharp systolic retraction was seen on the apex cardiogram, and there was only mild prolapse of one or both leaflets. Sharp systolic retractions occur on the apex cardiogram in the majority of patients with prolapsing mitral valves, and their presence suggests an abnormal contraction due to the systolic decompression of the left ventricle by the prolapsing mitral leaflets.