Abnormalities of left ventricular shape in patients with stable angina.

In this study, left ventricular shape was evaluated quantitatively by calculating the power spectrum and the regional curvatures of angiographic outlines as seen in the right oblique anterior projection. Two groups of patients were studied: 16 normal subjects and 16 patients with stable angina who were selected because of normal left ventricular function (normal left ventricular volumes, pressures, ejection fraction and no regional wall motion abnormality at subjective analysis of ventriculograms). The two groups did not differ in terms of mean age of the patients. Regional curvatures were calculated using the Frenet-Serret formula starting from the mitral corner (point 1) and extending to the aortic corner (point 90). The power spectrum was calculated by means of Fourier analysis. The ventricular shape during diastole of the patients with angina differed significantly from that of the normal group in that there was a greater posterobasal curvature; a lower curvature of the inferior wall showing an inward convexity; a greater parietal curvature of the inferoapical region and a minor curvature of the anterobasal region. The power spectrum differed significantly from that of the normal subjects. The 1st and 2nd harmonics were reduced and the 3rd, 4th, 5th and 6th ones increased. The end-systolic contour of the group of patients with stable angina showed a higher amplitude of the 3rd and 5th harmonics and a lower amplitude of the 1st, 2nd, 9th, 10th and 11th harmonics with respect to the group of normal patients. Regional curvatures showed significant differences between the two groups in the antero-basal region. These modifications of left ventricular shape in patients with stable angina did not appear to be related to age and/or heart rate; to abnormalities in hemodynamics and wall motion; or to acute ischemia. Abnormalities of shape in patients with stable angina, therefore, may indicate a remodeling of the left ventricle due to the structural effects (myocardial and/or interstitial) of chronic ischemia.