LONG-TERM EFFECTS OF EXCISION OF THE MITRAL APPARATUS ON GLOBAL AND REGIONAL VENTRICULAR-FUNCTION IN HUMANS

To evaluate the long-term sequelae of mitral valve excision on global and regional wall motion, contrast left ventriculograms from 21 patients with suspected prosthetic mitral valve dysfunction performed 10.4 ± 2.1 years after mitral valve replacement were analyzed by a computerized radial shortening method. Patients with significant coronary artery disease (>30% stenosis in any vessel) were excluded. In 8 of the 21 patients in whom preoperative ventriculograms were available, regional wall motion was normal before valve replacement. Although average radial shortening (35.6 ± 4.8% versus 35.3 ± 3.8%, p = NS) and left ventricular ejection fraction (62.8±4.2% versus 57.9 ± 2.8%, p = NS) were unchanged in the preoperative and postoperative studies of these eight patients, radial shortening in the vicinity of insertion of the posteromedial papillary muscle declined significantly (38.4 ± 6.4% to 20.8 ± 4.4%, p < 0.04). Postoperative radial shortening for all 21 patients at the site of insertion of the papillary muscle was also reduced to a significant degree compared with the average radial shortening (32.9 ± 10.3% versus 17.5±2.0%,p < 0.001). The findings demonstrate significant long-term and possibly permanent regional ventricular dysfunction after severing the chordae tendineae during mitral valve replacement. © 1990.