Okay T, Deligönül U, Sancaktar O, Kozan O
Bayindir Medical Center, Ankara, Turkey.
J Am Coll Cardiol. 1993 Nov 15;22(6):1691-6. doi: 10.1016/0735-1097(93)90597-t.
To explain the discrepancy between the symptomatic status of patients and the hemodynamically calculated mitral valve area during long-term follow-up after mitral balloon valvulotomy, mitral valve orifice variability after dobutamine infusion was investigated in two groups of patients.
A significant increase in aortic valve area with increased aortic transvalvular flow has been reported in patients with calcific aortic stenosis after aortic balloon valvulotomy. A similar phenomenon with regard to the mitral valve has not been studied in detail.
Group 1 comprised 10 patients (mean age 33 +/- 9 years) with untreated mitral stenosis. Group 2 comprised 29 consecutive patients (mean age 32 +/- 7 years) who underwent successful percutaneous mitral balloon valvulotomy 13 +/- 2 months before the study.
After dobutamine infusion, heart rate and cardiac index increased significantly in both groups. The mean pulmonary artery pressure, mitral valve gradient and pulmonary capillary pressure remained unchanged in Group 2 but increased significantly in Group 1. The mean mitral valve area was significantly larger in Group 2 after dobutamine infusion than at baseline (1.9 +/- 0.5 vs. 2.4 +/- 0.6 cm2, p < 0.0001) but was unchanged in Group 1 (1.2 +/- 0.2 vs. 1.3 +/- 0.3 cm2, p = NS). The mean mitral valve area in seven patients in Group 2 (24%) was < or = 1.5 cm2 before dobutamine infusion (1.3 +/- 0.4 cm2), which was defined as restenosis. In five of these seven patients who had minimal or no symptoms, the mitral valve area increased significantly after dobutamine infusion (1.3 +/- 0.1 vs. 1.9 +/- 0.1 cm2). In the other two patients who were symptomatic, the mitral valve area did not change after dobutamine infusion. These two patients were identified as having "true" restenosis, and redilation of the mitral valve was performed in both.
In patients who underwent mitral balloon valvulotomy, increased mitral valve reserve capacity contributed to symptomatic improvement on long-term follow-up. Dobutamine infusion may be helpful in detecting clinically significant restenosis.
为了解释二尖瓣球囊瓣膜成形术后长期随访期间患者症状状态与血流动力学计算的二尖瓣面积之间的差异，对两组患者多巴酚丁胺输注后的二尖瓣口变化情况进行了研究。
据报道，钙化性主动脉瓣狭窄患者在主动脉球囊瓣膜成形术后，随着主动脉跨瓣血流增加，主动脉瓣面积显著增大。关于二尖瓣的类似现象尚未进行详细研究。
第1组包括10例未经治疗的二尖瓣狭窄患者（平均年龄33±9岁）。第2组包括29例连续患者（平均年龄32±7岁），他们在研究前13±2个月接受了成功的经皮二尖瓣球囊瓣膜成形术。
多巴酚丁胺输注后，两组患者的心率和心脏指数均显著增加。第2组患者的平均肺动脉压、二尖瓣压差和肺毛细血管压保持不变，但第1组显著升高。多巴酚丁胺输注后，第2组患者的平均二尖瓣面积显著大于基线水平（1.9±0.5 vs. 2.4±0.6 cm²，p<0.0001），而第1组无变化（1.2±0.2 vs. 1.3±0.3 cm²，p=无统计学意义）。第2组7例患者（24%）在多巴酚丁胺输注前二尖瓣平均面积≤1.5 cm²（1.3±0.4 cm²），定义为再狭窄。这7例患者中，5例症状轻微或无症状，多巴酚丁胺输注后二尖瓣面积显著增加（1.3±0.1 vs. 1.9±0.1 cm²）。另外2例有症状的患者，多巴酚丁胺输注后二尖瓣面积未改变。这2例患者被确定为有“真性”再狭窄，并均接受了二尖瓣再扩张治疗。
在接受二尖瓣球囊瓣膜成形术的患者中，二尖瓣储备能力增加有助于长期随访中症状的改善。多巴酚丁胺输注可能有助于检测具有临床意义的再狭窄。
