[Comparison of preoperative and postoperative hemodynamic parameters in replacement or reconstruction of the mitral valve in ischemic dilated cardiomyopathy].

INTRODUCTION

Ischemic mitral insufficiency is a clinical syndrome described as a consequence of the coronary artery disease where the basic problem is blood regurgitation between the left ventricle and left atrium following mitral annulus dilatation. Mitral regurgitation occurs in different degrees during the natural evolution of the ischemic heart disease. The main reason for the existence of mitral regurgitation is global deterioration in the left ventricle geometry as a consequence of myocardial infarction or/and left ventricle dilatation. Surgical correction of this problem is possible by simultaneous correction of mitral insufficiency (repair or replacement) and complete myocardial revascularisation.

MATERIAL AND METHODS

Complete hemodynamic monitoring was followed by Swan-Ganz catheter including: central venous pressure, mean pulmonary artery pressure, pulmonary capillary wedge pressure, cardiac output, cardiac index and pulmonary vascular resistance. All surgical procedures were performed in extracorporeal circulation (ECC) with membrane oxygenator using moderate systemic hypothermia and transseptal surgical approach to mitral valve. Hemodynamic parameters were followed before and after ECC, immediately after surgery and during the first 48 hours after operation in the intensive care unit. In 88 patients posterior semicircular annuloplasty by N. Radovanović was performed whereas in 13 patients mitral valve replacement was done.

RESULTS

There is a great, statistically significant hemodynamic improvement after the surgical procedure and during the continuous 48 hours monitoring in the intensive care unit no matter if mitral repair or replacement was done. No statistically significant difference was recorded between these two groups considering that the hemodynamic improvement is very similar.

DISCUSSION

Simultaneous surgical procedures, including myocardial revascularization, mitral and usually consecutive tricuspid insufficiency correction, are a very common surgical problem with higher operative risk than isolated coronary bypass procedures. In 88 cases where mitral reconstruction was possible, posterior semicircular reductive annuloplasty was performed. Thus mitral annulus area reduction is achieved preserving its physiologic shape and avoiding rigidity. Mitral valve replacement includes implantation of the latest generation of bileaflet valve prosthesis and operative technique that preserves subvalvular apparatus to maintain myocardial contractility as much as possible. This policy and also good immediate postoperative care, improve the hemodynamic status in both groups.

CONCLUSION

All hemodynamic parameters followed by ECC and 48 hours in the intensive care unit were significantly improved no matter whether mitral reconstruction or replacement was done. There is no statistically significant difference in hemodynamic parameters and clinical improvement between these two groups. Carefully chosen operative tactic and techniques as well as good preoperative and postoperative care may explain these very good results.