Bach D S, Armstrong W F
Department of Internal Medicine, University of Michigan, Ann Arbor, USA.
Am J Cardiol. 1995 Aug 1;76(4):259-62. doi: 10.1016/s0002-9149(99)80077-0.
Arbutamine is a new, potent, short-acting synthetic catecholamine developed specifically for use as a cardiac stress agent. Previous reports on the accuracy of arbutamine for the detection of coronary artery disease have relied on heart rate (HR) increases similar to those seen at peak exercise. This study was undertaken to test the potential to provoke ischemic wall motion abnormalities on echocardiography using arbutamine at a HR below that associated with peak exercise. One hundred forty-six patients with coronary artery disease underwent computerized closed-loop stress testing with arbutamine; 120 (82%) had echocardiographic images adequate for analysis at baseline, low stress (20 beats/min above baseline), and peak stress (target of 85% age-predicted peak HR). Ejection fraction increased from 59 +/- 10% at baseline to 72 +/- 12% at low stress, and remained stable at 72 +/- 14% at peak stress. Of 88 patients with echocardiographic evidence of ischemia at peak stress, 73 (83%) had evidence of ischemia at low stress. Change in wall motion score index from baseline to low stress represented 62% of the change noted from baseline to peak stress. A greater number of stenotic vessels were associated with a somewhat higher proportion of ischemic responses evident at low stress. The present study suggests that the maximal inotropic effects of arbutamine may occur at a dose lower than that required for maximal chronotropic effect. In the future, it may be possible to establish an infusion end point for arbutamine stress testing using a HR < 85% of the age-predicted maximum.
阿巴胺是一种新的、强效的、短效的合成儿茶酚胺，专门开发用作心脏应激剂。先前关于阿巴胺检测冠状动脉疾病准确性的报告依赖于心率（HR）增加，类似于运动峰值时所见。本研究旨在测试使用低于运动峰值相关心率的阿巴胺在超声心动图上诱发缺血性室壁运动异常的可能性。146例冠状动脉疾病患者接受了阿巴胺计算机化闭环应激测试；120例（82%）在基线、低应激（比基线高20次/分钟）和峰值应激（目标为年龄预测峰值心率的85%）时有足够的超声心动图图像用于分析。射血分数从基线时的59±10%增加到低应激时的72±12%，在峰值应激时保持稳定，为72±14%。在88例峰值应激时有超声心动图缺血证据的患者中，73例（83%）在低应激时有缺血证据。室壁运动评分指数从基线到低应激的变化占从基线到峰值应激变化的62%。更多的狭窄血管与低应激时明显更高比例的缺血反应相关。本研究表明，阿巴胺的最大正性肌力作用可能在低于最大变时性作用所需剂量时出现。未来，有可能使用低于年龄预测最大值85%的心率来确定阿巴胺应激测试的输注终点。
