[Radioisotopic quantification of isolated mitral insufficiency]

A group of 23 consecutive patients with isolated mitral regurgitation confirmed by angiography, 8 of whom had normal and 15 abnormal coronary arteriographies, were compared with a control group of 27 subjects without valvular heart disease (normal coronary arteriography in 7 cases, abnormal coronary arteriography in 20 cases). After injection of technetium 99m labelled albumin, gamma-angiocardiography was performed in the left anterior oblique plane at equilibrium with electrocardiographic synchronisation. Fourier's analysis of the images excluded hepatic pulsation and dephasing of the two ventricles: amplitude images were used to trace the right and left ventricular zones of interest. The ratio of right to left ventricular ejection fraction was calculated in these zones from the radioactive count at end diastole and end systole. The ratio of the ejection fractions was 1.15 +/- 0.18 in subjects without valvular disease compared to 2.66 +/- 0.47 in patients with mitral regurgitation and normal coronary arteries, and 2.50 +/- 1.28 in mitral regurgitation with coronary artery disease (no significant difference between these two sub-groups). When compared with angiographic quantification of the mitral regurgitation, the ratio of ejection fractions increased progressively with the severity of the leak: 1.81 +/- 0.44 for grade I (9 cases), 2.37 +/- 0.80 for grade 2 (5 cases), 3.02 +/- 1.07 for grade 3 (4 cases) and 3.73 +/- 1.50 for grade 4 (5 cases). The differences between each sub-group are not statistically significant because of the small number of patients in each sub-group but all the values are significantly higher than the reference values.(ABSTRACT TRUNCATED AT 250 WORDS)