Evaluation of hemodynamic changes in patients with mitral valve replacement using dobutamine stress echocardiography.

OBJECTIVE: The aim of this study was to investigate the response of heart to stress according to the size of the prosthetic valve in patients who had undergone mitral valve replacement by using dobutamine stress echocardiography (DSE) and to evaluate the relationship between the size of the prosthetic valve and cardiac recovery-remodeling process. METHODS: Thirty-nine patients, who had undergone mitral valve replacement were compared in terms of left ventricular diameters, systolic functions and cardiac mass indexes in order to investigate the effect of the mechanical valve size on postoperative cardiac remodeling in this longitudinal study. They were divided into three groups according to their valve size: Group 1 (valve size<29 mm, n=11), Group 2 (valve size=29 mm, n=11) and Group 3 (valve size>29 mm, n=17). Statistical analysis was performed using Chi-square and one-way ANOVA tests to determine the statistical differences between the groups. The repeated measurements of two-way ANOVA test was used to analyze effects during long-term follow-up. RESULTS: Only Group 1 patients achieved a significant decrease in terms of left ventricular mass index and end-diastolic diameter (138.3+/-29.7 g/m2 vs 86.6+/-15.6 g/m2 and 5.1+/-0.5 cm vs. 4.4+/-0.4 cm, p<0.05). Group 3 patients' left ventricular ejection fraction become worse after the operation (64.0+/-5.6% vs. 55.9+/-6.5%, p<0.05). Maximum and mean pressure gradients across the mitral prosthesis as well as pulmonary artery pressure were significantly increased in all groups during DSE. Maximum gradients increased from 14.2+/-4.6 to 20.7+/-7.5 mmHg in Group 1 (p<0.05), 11.6+/-4.7 to 16.2+/-6.8 mmHg in Group 2 (p<0.05), and 10.6+/-3.1 to 20.8+/-12.7 mmHg in Group 3 (p<0.05). Isovolumic relaxation time decreased in all groups following the dobutamine infusion, as expected, but this decline was not significant in Group 3. CONCLUSION: A worsening in left ventricular systolic function was observed in large- sized valve prosthesis group. Only the patients who had undergone MVR with small-sized valve prosthesis achieved a decrease in cardiac mass index and preservation of the systolic function. The echocardiographically determined differences and mass index that appeared after the operation may point out that, the effect of the operation on cardiac remodeling can be related with the ventricular size.

The place of closed mitral valvotomy in the modern cardiac surgery era.

BACKGROUND AND AIM OF THE STUDY: The study aim was to investigate the long-term efficacy of closed mitral valvotomy (CMV). METHODS: Data obtained over a 36-year period from 1,134 patients who underwent CMV were analyzed. The analysis was carried out retrospectively from hospital records, with follow up examinations being conducted mainly at the outpatient clinic. RESULTS: In-hospital mortality (< or = 30 days after surgery) was 0.4% (n = 5, all closed procedures). Cardiac failure was the main cause of early death, and postoperative peripheral embolism occurred in five cases (0.5%). Freedom from thromboembolism was 99.0 +/- 0.5% at 36 years. Operative results were satisfactory in most patients, and severe mitral incompetence was seen only in three cases. Post-valvotomy mitral regurgitation occurred in 88 patients (7.7%) during the first year after CMV. Reoperation was performed in 500 patients (44.1%). The mean interval between CMV and reoperation was 141.1 +/- 80.8 months (range: 1-436 months). Fourteen patients were reoperated on for mitral regurgitation, 485 for mitral restenosis, and five for mixed mitral valve disease (stenosis and regurgitation). Freedom from reoperation after CMV was 81.4 +/- 1.3% at 10 years, 16.4 +/- 2.1% at 20 years, 3.1 +/- 1.2% at 20 years, and 0% at 36 years. Cox regression analysis indicated that impaired functional capacity, reduced mitral valve area, gradual increase in left atrial diameter and postoperative mitral insufficiency increased the reoperation rate after CMV. CONCLUSION: When compared with percutaneous balloon or surgical open valvotomy, CMV represents a satisfactory technique in terms of simplicity, high efficacy and lower cost.