Waters D D, McCans J L, Crean P A
J Am Coll Cardiol. 1985 Nov;6(5):1011-5. doi: 10.1016/s0735-1097(85)80302-8.
To investigate the frequency and mechanism of variable threshold angina, seven treadmill exercise tests were performed in each of 28 patients with stable effort angina and exercise-induced ST segment depression. Each patient had tests at 8 AM on 4 days within a 2 week period and on 1 of these days had three additional tests at 9 AM, 11 AM and 4 PM. Time to 1 mm ST depression increased from 277 +/- 172 seconds on day 1 to 319 +/- 186 seconds on day 2, 352 +/- 213 seconds on day 3 and 356 +/- 207 seconds on day 4 (p less than 0.05). Rate-pressure product at 1 mm ST depression remained constant. Similarly, time to 1 mm ST depression increased from 333 +/- 197 seconds at 8 AM to 371 +/- 201 seconds at 9 AM and to 401 +/- 207 seconds at 11 AM and decreased to 371 +/- 189 seconds at 4 PM (p less than 0.01). Again, rate-pressure product at 1 mm ST depression remained constant. The standard deviation for time to 1 mm ST depression, calculated as a percent of the mean for each patient's seven tests and then averaged for the entire group, was 22 +/- 11%. The standard deviation for rate-pressure product at 1 mm ST depression, calculated in the same way, was significantly less at 8.4 +/- 2.8% (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
为研究变异性阈值心绞痛的发生频率及机制，对28例稳定型劳力性心绞痛且运动诱发ST段压低的患者，每人进行了7次平板运动试验。每位患者在2周内的4天上午8点进行试验，其中1天在上午9点、11点和下午4点额外增加3次试验。发生1毫米ST段压低的时间从第1天的277±172秒增加到第2天的319±186秒、第3天的352±213秒和第4天的356±207秒（p<0.05）。1毫米ST段压低时的心率血压乘积保持不变。同样，发生1毫米ST段压低的时间从上午8点的333±197秒增加到上午9点的371±201秒、上午11点的401±207秒，下午4点降至371±189秒（p<0.01）。1毫米ST段压低时的心率血压乘积再次保持不变。将每位患者7次试验的1毫米ST段压低时间的标准差计算为平均值的百分比，然后对整个组进行平均，为22±11%。以同样方式计算的1毫米ST段压低时心率血压乘积的标准差显著更低，为8.4±2.8%（p<0.001）。（摘要截断于250字）
