Grimaldi Antonio, De Bonis Michele, Pappalardo Federico, Taramasso Maurizio, Verzini Alessandro, Calabrese Maria Chiara, Maisano Francesco, Alfieri Ottavio
Cardiovascular and Thoracic Surgery Department, San Raffaele Scientific Institute, Milan, Italy.
J Heart Valve Dis. 2012 Jul;21(4):446-53.
The study aim was to assess if an undersized mitral annuloplasty for functional mitral regurgitation (FMR) in dilated cardiomyopathy can determine a clinically relevant mitral stenosis during exercise.
Both, rest and stress echocardiography were performed in 12 patients submitted to an undersized ring annuloplasty for FMR in dilated cardiomyopathy. The mean ring size was 27 +/- 1.3 mm. All patients were in NYHA functional classes I-II, were in stable sinus rhythm, and without significant residual mitral regurgitation (grade < or = 2/4).
At peak exercise (mean 81 +/- 12 W), the main cardiac performance indices were significantly improved, including systolic blood pressure (121 +/- 5.6 versus 169 +/- 14 mmHg, p < 0.001), stroke volume (63 +/- 15 versus 77 +/- 14 ml, p < 0.001), left ventricular ejection fraction (43 +/- 9% versus 47 +/- 9%, p = 0.001), and systolic right ventricular function (pulsed tissue Doppler index peak systolic velocity: 8.6 +/- 1.7 versus 11.1 +/- 3.2 cm/s, p = 0.004). A mild increase in planimetric mitral valve area was observed at peak exercise (2.12 +/- 0.4 versus 2.17 +/- 0.3 cm2, p = 0.05). Although the transmitral mean gradient was increased from 3.2 +/- 1.2 to 6.3 +/- 2.3 mmHg (p < 0.0001), the systolic pulmonary artery pressure did not change significantly (27 +/- 2.8 versus 30.1 +/- 6.4 mmHg, p = 0.3), thus revealing a preserved cardiac adaptation to exercise.
In these preliminary data, postoperative clinically relevant mitral stenosis was not observed in patients submitted to mitral repair for FMR. Stress echocardiography represents a valuable tool to assess an appropriate cardiac response to exercise and to detect a significant exercise-induced pulmonary hypertension after undersized annuloplasty ring surgery.
本研究旨在评估扩张型心肌病功能性二尖瓣反流（FMR）患者行过小尺寸二尖瓣环成形术是否会在运动时导致具有临床意义的二尖瓣狭窄。
对12例因扩张型心肌病FMR行过小尺寸二尖瓣环成形术的患者进行静息和负荷超声心动图检查。平均环尺寸为27±1.3mm。所有患者均处于纽约心脏病协会（NYHA）心功能I-II级，窦性心律稳定，且无明显残余二尖瓣反流（≤2/4级）。
在运动峰值时（平均81±12W），主要心脏功能指标显著改善，包括收缩压（121±5.6对169±14mmHg，p<0.001）、每搏量（63±15对77±14ml，p<0.001）、左心室射血分数（43±9%对47±9%，p = 0.001）以及收缩期右心室功能（脉冲组织多普勒指数峰值收缩速度：8.6±1.7对11.1±3.2cm/s，p = 0.004）。运动峰值时二尖瓣平面面积轻度增加（2.12±0.4对2.17±0.3cm²，p = 0.05）。虽然二尖瓣平均跨瓣压差从3.2±1.2mmHg增加到6.3±2.3mmHg（p<0.0001），但收缩期肺动脉压无显著变化（27±2.8对30.1±6.4mmHg，p = 0.3），表明心脏运动适应性良好。
根据这些初步数据，FMR二尖瓣修复术后患者未观察到具有临床意义的二尖瓣狭窄。负荷超声心动图是评估心脏对运动的适当反应以及检测过小尺寸二尖瓣环成形术环手术后显著运动诱发肺动脉高压的有价值工具。
