The Effect of Preoperative Pulmonary Arterial Pressure and Right Ventricular Function on the Changes in Right Ventricular Function after Mitral Valve Replacement

Background: In patients with mitral valvular disease with pulmonary hypertension (PHT) accompanying right ventricular (RV) dysfunction, mitral valve replacement (MVR) improves RV function and other hemodynamic variables in long term follow-up. However, there are controversies in improvement of RV function in the immediate postoperative period. We compared the RV function immediately after a MVR with a pulmonary artery catheter (PAC) between patients with normal and decreased RV function with PHT preoperatively. Methods: Twenty nine patients undergoing a MVR were included in the study. The patients (n = 14) with mean pulmonary arterial pressure (PAP) ≤ 25 mmHg were assigned to group I and the patients (n = 15) with mean PAP ⁡ 25 mmHg were assigned to group II. A PAC with rapid response-thermistors which enables us to determine right ventricular ejection fraction (RVEF) was inserted in all patients and hemodynamic variables were measured before and after cardiopulmonary bypass (CPB). Results: After CPB, PAP, pulmonary vascular resistance index (PVRI), and RV end-diastolc volume (RVEDV) were significantly decreased and RVEF was significantly increased in group II compared with group I in which no hemodynamic variables were changed. Conclusions: A MVR decreased RV afterload and increased RV function more significantly in patients with preoperative PHT accompanying RV dysfunction than in patients with normal PAP preoperatively.ope