Koike A, Itoh H, Doi M, Taniguchi K, Marumo F, Umehara I, Hiroe M
Second Department of Internal Medicine, Tokyo Medical and Dental University, Japan.
Jpn Circ J. 1990 Dec;54(12):1535-45. doi: 10.1253/jcj.54.12_1535.
Acute effects of oral isosorbide dinitrate on exercise capacity were evaluated in 14 patients with chronic heart disease measuring the anaerobic threshold and left ventricular function during exercise. A symptom-limited exercise test was performed on a bicycle ergometer with work rates increased by 1W every 6 seconds. Left ventricular function was continuously monitored with a computerized cadmium telluride detector following the intravenous injection of technetium-labeled red blood cells. Thirty minutes after the control exercise test, patients were given isosorbide dinitrate, 5 mg orally. The second exercise test was performed 30 min later. Isosorbide dinitrate improved the anaerobic threshold from 715.4 +/- 172.9 to 774.9 +/- 173.5 ml/min (p less than 0.01) and ejection fraction at peak exercise from 36.7 +/- 11.6 to 39.9 +/- 12.3% (p less than 0.05). However, there was no significant change in maximum work rate or peak oxygen uptake. Those patients for whom isosorbide dinitrate resulted in a 10% or greater improvement in the anaerobic threshold had both higher pre-treatment ejection fractions and greater increases in peak exercise ejection fraction following isosorbide dinitrate. Measurements of the anaerobic threshold and left ventricular function during exercise may be useful in the evaluation of the efficacy of vasodilators in cardiac patients.
通过测量14例慢性心脏病患者运动期间的无氧阈值和左心室功能，评估口服硝酸异山梨酯对运动能力的急性影响。在自行车测力计上进行症状限制性运动试验，工作速率每6秒增加1W。静脉注射锝标记的红细胞后，用计算机化碲化镉探测器连续监测左心室功能。在对照运动试验30分钟后，给患者口服5mg硝酸异山梨酯。30分钟后进行第二次运动试验。硝酸异山梨酯使无氧阈值从715.4±172.9提高到774.9±173.5ml/min（p<0.01），运动峰值时的射血分数从36.7±11.6提高到39.9±12.3%（p<0.05）。然而，最大工作速率或峰值摄氧量没有显著变化。硝酸异山梨酯使无氧阈值提高10%或更多的患者，治疗前射血分数较高，服用硝酸异山梨酯后运动峰值时的射血分数增加幅度更大。运动期间测量无氧阈值和左心室功能可能有助于评估血管扩张剂对心脏病患者的疗效。
