Koike A, Hiroe M, Yajima T, Adachi H, Shimizu N, Kano H, Sugimoto K, Miyahara Y, Korenaga M, Marumo F
Second Department of Internal Medicine, Tokyo Medical and Dental University, Japan.
Am J Cardiol. 1995 Sep 1;76(7):449-52. doi: 10.1016/s0002-9149(99)80128-3.
The beneficial effects of coronary vasodilators on exercise capacity in patients with angina pectoris are well known. However, their effects on oxygen uptake (VO2) kinetics at the onset of exercise have not been elucidated. The present study was undertaken to determine the acute effects of nicorandil, a newer coronary vasodilator, on the kinetics of VO2 at the onset of exercise in patients with ischemic heart disease. Ten patients with significant coronary stenosis performed constant mild-intensity cycle exercise (32 +/- 3 W) for 6 minutes after oral administration of 10 mg of nicorandil or an identical placebo in a double-blind, crossover manner. Nicorandil had no effect on resting heart rate, blood pressure, or VO2. However, the time constant for the increase in VO2 during constant work rate exercise was significantly shorter (the kinetics of VO2 were faster) after administration of nicorandil than after placebo (46.5 +/- 13.3 vs 51.1 +/- 11.9 seconds; p = 0.039). The increase in VO2 at 6 minutes compared with 3 minutes of constant work, which reflects the VO2 kinetics, also was reduced with nicorandil (3.8 +/- 37.9 vs 27.5 +/- 27.1 ml/min; p = 0.022). Nicorandil was found to increase the rate of VO2, increase during the onset of constant work rate exercise, probably as a result of an improved response in cardiac output. Analysis of VO2 kinetics provides new and useful parameters for the evaluation of circulatory adjustments at the onset of exercise in patients with ischemic heart disease.
冠状动脉血管扩张剂对心绞痛患者运动能力的有益作用是众所周知的。然而，它们对运动开始时氧摄取（VO₂）动力学的影响尚未阐明。本研究旨在确定新型冠状动脉血管扩张剂尼可地尔对缺血性心脏病患者运动开始时VO₂动力学的急性影响。10例冠状动脉严重狭窄患者以双盲、交叉方式口服10mg尼可地尔或相同安慰剂后，进行6分钟的恒定轻度强度循环运动（32±3W）。尼可地尔对静息心率、血压或VO₂无影响。然而，在恒定工作率运动期间，尼可地尔给药后VO₂增加的时间常数明显缩短（VO₂动力学更快），而安慰剂给药后为（46.5±13.3秒对51.1±11.9秒；p=0.039）。与3分钟恒定工作相比，6分钟时VO₂的增加反映了VO₂动力学，尼可地尔给药后也有所降低（3.8±37.9对27.5±27.1ml/min；p=0.022）。发现尼可地尔可增加VO₂的速率，在恒定工作率运动开始时增加，这可能是由于心输出量反应改善的结果。VO₂动力学分析为评估缺血性心脏病患者运动开始时的循环调节提供了新的有用参数。
