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 (greater than 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 less than 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 less than 0.001). The findings demonstrate significant long-term and possibly permanent regional ventricular dysfunction after severing the chordae tendineae during mitral valve replacement.