Hemodynamics in Ruptured Chordae Tendineae and Chronic Rheumatic Mitral Regurgitation

Abstract

Twenty-five patients with proven ruptured mitral chordae tendineae and 25 patients with chronic rheumatic mitral regurgitation were studied with quantitative biplane left-heart angiocardiography. Compared to the rheumatic patients, the ruptured chordae group had strikingly smaller left atrial maximum volume (mean: 119 ± 47 vs 267 ± 131 ml/m ² mean) and less compliant left atrium (mean: 1.61 ± 1.52 vs 5.14 ± 4.31 ml/mm Hg-m ² ); less impressively but significantly smaller left ventricular end-diastolic volume (mean: 142 ± 43 vs 188 ± 75 ml/m ² ) and mass (mean: 133 ± 27 vs 166 ± 50 mm/m ² ), and relatively insignificant tendency toward smaller left ventricular stroke volume and regurgitant flow per stroke. Ejection fractions, ventricular pressures, and forward flow per stroke were not significantly different. Within the ruptured chordae group, the duration of heart failure was not significantly correlated with any hemodynamic variable. These results indicate quantitatively the spectrum of abnormal hemodynamics in these two different etiologic forms of mitral insufficiency. The most striking differences between the two groups are in atrial dynamics. In spite of the usually more acute nature of ruptured chordae, significant compensatory dilatation and hypertrophy of the left ventricle is common in those patients. In both groups, large regurgitant flows with relatively normal ventricular function as expressed by ejection fraction is the usual finding.