Stoll B C, Ashcom T L, Johns J P, Johnson J E, Rubal B J
Department of Medicine, Brooke Army Medical Center, Fort Sam Houston, Texas 78234-6262.
Am J Cardiol. 1995 Mar 1;75(7):482-4. doi: 10.1016/s0002-9149(99)80585-2.
Beta-blocker therapy remains controversial in patients with mitral stenosis. In this randomized, double-blind, crossover, placebo-controlled study, the effects of atenolol (50 and 100 mg/day) were assessed in 15 patients (aged 46 +/- 11 years) with mitral stenosis (mean valve area 1.0 +/- 0.4 cm2; New York Heart Association class II or III) at rest and during upright bicycle ergometry. Doppler echocardiography was used to compare heart rate, cardiac and stroke volume indexes, diastolic filling period, and peak and mean transmitral gradients; a metabolic cart was used to obtain maximal oxygen consumption, carbon dioxide production, and anaerobic threshold. Beta-blocking therapy did not improve exercise time, external work, maximal oxygen consumption rate, or anaerobic threshold. Compared with placebo, maximal oxygen consumption rate and cardiac index decreased (p < 0.05) > 11% and > 20%, respectively, with atenolol at peak exercise. Although heart rate was reduced > 20% and diastolic filling period prolonged > 40% by atenolol at rest and exercise (p < 0.05), stroke volume index changed little compared with placebo. The data suggest that despite lower transvalvular pressure gradients, little benefit in exercise performance is achieved with beta-blocker therapy in patients with severe mitral stenosis.
β受体阻滞剂治疗二尖瓣狭窄患者仍存在争议。在这项随机、双盲、交叉、安慰剂对照研究中，对15例二尖瓣狭窄患者（年龄46±11岁，平均瓣膜面积1.0±0.4 cm²；纽约心脏协会心功能II级或III级）在静息状态及直立自行车运动试验期间评估了阿替洛尔（50和100 mg/天）的效果。采用多普勒超声心动图比较心率、心排血量和每搏量指数、舒张充盈期以及二尖瓣跨瓣压差峰值和平均值；使用代谢车获取最大摄氧量、二氧化碳生成量和无氧阈。β受体阻滞剂治疗未改善运动时间、外部做功、最大摄氧率或无氧阈。与安慰剂相比，在运动峰值时，阿替洛尔使最大摄氧率和心脏指数分别下降>11%和>20%（p<0.05）。尽管在静息和运动时阿替洛尔使心率降低>20%，舒张充盈期延长>40%（p<0.05），但与安慰剂相比，每搏量指数变化不大。数据表明，尽管二尖瓣跨瓣压差降低，但β受体阻滞剂治疗对重度二尖瓣狭窄患者的运动能力改善甚微。
