Morizuki O, Kawauchi M, Furuse A
Department of Thoracic Surgery, Faculty of Medicine, University of Tokyo.
J Cardiol. 1994 May-Jun;24(3):199-202.
The exercise stress test with a semi-supine position bicycle ergometer was evaluated in 10 normal subjects and five cardiac patients to define the appropriate target heart rate for exercise echocardiography. The normal healthy subjects were aged between 24 and 30 years, while the five patients with artificial aortic valves were aged between 13 and 54 years. The workload was continuously increased from 0 W to the maximum achieved workload at 20 W/min for normal subjects and 10 W/min for patients. Echocardiography was recorded every minute during the test procedure. End-diastolic and end-systolic dimensions were measured and ejection fraction was calculated. The ejection fraction at heart rates 50, 60, 70 and 80% of predicted maximum heart rate and at maximum workload were compared. Heart rates at the maximum workload for normal subjects were 76 to 94% (86.3 +/- 6.3%) of the maximum heart rate predicted from the age of the subjects and 70 to 102% (84.0 +/- 12.6%) for the patients. The largest election fraction values during exercise stress were obtained at 70% of the maximum predicted heart rate in normal subjects, and at 60% in the patients. The target heart rate for exercise echocardiography is 70% of the maximum calculated heart rate.
对10名正常受试者和5名心脏病患者进行了半卧位自行车测力计运动应激试验，以确定运动超声心动图的合适目标心率。正常健康受试者年龄在24至30岁之间，而5名有人工主动脉瓣的患者年龄在13至54岁之间。对于正常受试者，工作量以20W/分钟的速度从0W持续增加到达到的最大工作量；对于患者，工作量以10W/分钟的速度增加。在测试过程中每分钟记录一次超声心动图。测量舒张末期和收缩末期尺寸并计算射血分数。比较了预测最大心率的50%、60%、70%和80%以及最大工作量时的射血分数。正常受试者在最大工作量时的心率为受试者年龄预测最大心率的76%至94%（86.3±6.3%），患者为70%至102%（84.0±12.6%）。运动应激期间最大射血分数值在正常受试者为预测最大心率的70%时获得，在患者中为60%时获得。运动超声心动图的目标心率为计算出的最大心率的70%。
