Ashcom T L, Johns J P, Bailey S R, Rubal B J
Department of Medicine, Brooke Army Medical Center, Fort Sam Houston, Texas, USA.
Cathet Cardiovasc Diagn. 1995 Jun;35(2):110-5. doi: 10.1002/ccd.1810350206.
beta-blocker therapy for mitral stenosis is controversial. This study compares right and left heart hemodynamics at rest and supine submaximal exercise in patients (n = 7) receiving chronic beta-antagonists with untreated patients (n = 17) matched for age (mean +/- SD = 51 +/- 12 years) and valve area (0.7 +/- 0.2 cm2/m2). Little benefit was observed with treatment at rest. Although pulmonary capillary wedge pressures (PCWP) were lower during exercise in the beta-blocker group (22 +/- 4 vs. 31 +/- 9 mmHg; P < 0.05), exercise performance was not enhanced and cardiac output response during exercise was reduced (control = 41% increase vs. 12% for beta-blockade). PCWP rose rapidly when diastolic filling periods were < 300 msec in both groups. Pulmonary capillary wedge pressure was found to be a nonlinear functions (P < 0.001) of diastolic filling period (PCWP = 15.9 + 5.84 x 10(5)/dfp2). These data suggest that there is a critical heart rate in patients with mitral stenosis above which hemodynamic compromise rapidly occurs.
β受体阻滞剂治疗二尖瓣狭窄存在争议。本研究比较了接受慢性β受体拮抗剂治疗的患者（n = 7）与未治疗患者（n = 17）在静息和仰卧位次极量运动时的左右心血流动力学，两组患者年龄（平均±标准差= 51±12岁）和瓣膜面积（0.7±0.2 cm2/m2）相匹配。静息时治疗效果不明显。虽然β受体阻滞剂组运动时肺毛细血管楔压（PCWP）较低（22±4 vs. 31±9 mmHg；P < 0.05），但运动能力并未增强，且运动时心输出量反应降低（对照组增加41%，β受体阻滞剂组增加12%）。两组中当舒张期充盈时间< 300毫秒时，PCWP迅速升高。发现肺毛细血管楔压是舒张期充盈时间的非线性函数（P < 0.001）（PCWP = 15.9 + 5.84 x 10(5)/dfp2）。这些数据表明，二尖瓣狭窄患者存在一个临界心率，超过该心率血流动力学迅速受损。
