Objective: To explore whether successful valvuloplasty increases mitral valve reserve capacity in patients with mitral stenosis. Methods: Thirty-eight patients with pure rheumatic mitral stenosis underwent isoproteren...Objective: To explore whether successful valvuloplasty increases mitral valve reserve capacity in patients with mitral stenosis. Methods: Thirty-eight patients with pure rheumatic mitral stenosis underwent isoproterenol stress echocardiography before and after successful percutaneous balloon valvuloplasty. The mitral valve area (by direct planimetry of two-dimensional echocardiography), mean transmitral pressure gradient (by continuous-wave Doppler echocardiography), and cardiac output (by M-mode echocardiography) were measured at rest and under isoproterenol infusion to achieve heart rate of different stages. Results:Between the measurements before and after valvuloplasty, significant differences were observed in the mitral valve area (0. 91±0. 28 vs 1. 87±0. 23 cm2, P<0. 01), mean transmitral pressure gradient (12. 5±6. 3 vs 3. 9±1. 9 mmHg, P<0. 01) and cardiac output (3. 93±1. 44 vs 4. 73±1. 01 L/min, P<0. 05) at rest. Before valvuloplasty, the mean transmitral pressure gradient increased significantly (P<0. 01) as heart rate increased, but there were no significant differences in the measurements of mitral valve area and cardiac output (both P>0. 05). In contrast, there was a significant increase after valvuloplasty in the mean transmitral pressure gradient (P<0. 01), but both mitral valve area and cardiac output further increased (both P< 0. 01) as heart rate increased. Moreover, valvuloplasty decreased the mean transmitral pressure gradient at peak heart rate from 23. 0±4. 5 to 7. 75±2. 30 mmHg (F<0. 01) under submaximal stress. Conclusion: Successful percutaneous balloon valvuloplasty soon causes a significant increase of mitral valve reserve capacity in patients with mitral stenosis, which is conspicuously manifested under condition of hemodynamic stress. Stress echocardiography provides a safe, feasible and non-invasive means of assessing the reserve capacity.展开更多
文摘Objective: To explore whether successful valvuloplasty increases mitral valve reserve capacity in patients with mitral stenosis. Methods: Thirty-eight patients with pure rheumatic mitral stenosis underwent isoproterenol stress echocardiography before and after successful percutaneous balloon valvuloplasty. The mitral valve area (by direct planimetry of two-dimensional echocardiography), mean transmitral pressure gradient (by continuous-wave Doppler echocardiography), and cardiac output (by M-mode echocardiography) were measured at rest and under isoproterenol infusion to achieve heart rate of different stages. Results:Between the measurements before and after valvuloplasty, significant differences were observed in the mitral valve area (0. 91±0. 28 vs 1. 87±0. 23 cm2, P<0. 01), mean transmitral pressure gradient (12. 5±6. 3 vs 3. 9±1. 9 mmHg, P<0. 01) and cardiac output (3. 93±1. 44 vs 4. 73±1. 01 L/min, P<0. 05) at rest. Before valvuloplasty, the mean transmitral pressure gradient increased significantly (P<0. 01) as heart rate increased, but there were no significant differences in the measurements of mitral valve area and cardiac output (both P>0. 05). In contrast, there was a significant increase after valvuloplasty in the mean transmitral pressure gradient (P<0. 01), but both mitral valve area and cardiac output further increased (both P< 0. 01) as heart rate increased. Moreover, valvuloplasty decreased the mean transmitral pressure gradient at peak heart rate from 23. 0±4. 5 to 7. 75±2. 30 mmHg (F<0. 01) under submaximal stress. Conclusion: Successful percutaneous balloon valvuloplasty soon causes a significant increase of mitral valve reserve capacity in patients with mitral stenosis, which is conspicuously manifested under condition of hemodynamic stress. Stress echocardiography provides a safe, feasible and non-invasive means of assessing the reserve capacity.
