SHORT-TERM HEMODYNAMIC EVALUATION OF CIRCUMFERENTIAL MITRAL ANNULOPLASTY FOR CORRECTION OF MITRAL-VALVE REGURGITATION IN DOGS

Objective-To determine the short-term hemodynamic effects associated w ith circumferential mitral annuloplasty (CMA) in dogs with mitral regu rgitation. Study Design-Prospective experimental study. Animals-Seven healthy adult mongrel dogs. Methods-Mitral regurgitation was surgicall y induced, and annular dilation occurred. Echocardiography and cardiac catheterization were used to determine forward ejection fraction (FEF ), regurgitant fraction (RF), pulmonary capillary wedge pressure (PCWP ), and annular diameter before and immediately after CMA in five dogs. FEF and RF were also evaluated 7 days after annuloplasty. Results-Mea n annular diameter and PCWP were significantly reduced immediately aft er CMA. Significant increases in FEF of 19% and 22%, were shown immedi ately and 7 days after CMA. Significant reductions in RF of 19% and 22 % were also shown immediately and 7 days after annuloplasty. Conclusio ns-Sustained hemodynamic benefits and a reduction in annular diameter were achieved by CMA in a canine model of mitral regurgitation. Clinic al Implications-CMA may be a suitable treatment for heart failure beca use of mitral regurgitation when early signs of cardiovascular decompe nsation persist despite appropriate medical management. (C) Copyright 1998 by The American College of Veterinary Surgeons.