Sansoy V, Watson D D, Beller G A
Cardiovascular Division, University of Virginia Health Sciences Center, Charlottesville 22908, USA.
Am J Cardiol. 1997 Mar 15;79(6):709-12. doi: 10.1016/s0002-9149(96)00854-5.
The supplementary value of varying degrees of upsloping ST-segment depression observed during treadmill exercise testing to the accuracy of the exercise ST-segment response for detection of ischemia was determined by employing a reversible thallium-201 (201Tl) defect as the criteria for ischemia. A group of 199 consecutive patients (168 men) with > or = 1 reversible 201Tl defects on quantitative planar perfusion imaging, and a normal group of 366 patients with normal 201Tl scans who achieved > or = 85% of age-predicted maximum heart rate were studied. Upsloping ST-segment depression was subcategorized for > or = 1.0, > or = 1.5, and > or = 2.0 mm of sustained ST-segment depression below baseline at 0.08 seconds after the J-point. If only > or = 1.0 mm of horizontal or downsloping ST-segment depression was designated as abnormal and all upsloping responses as normal, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the exercise electrocardiogram were 49% (98 of 199), 84% (281 of 336), 64% (98 of 153), 74% (281 of 382), and 71% (379 of 535), respectively. If in addition to > 1.0 mm of horizontal or downsloping ST-segment depression, > or = 2.0 mm of upsloping ST-segment depression is considered abnormal, these values were 52% (104 of 199), 81% (272 of 336), 62% (104 of 168), 74% (272 of 367), and 70% (376 of 535), respectively. If > or = 1.5 mm of upsloping ST-segment depression is considered an abnormal response, these values were 59% (117 of 199), 74% (248 of 336), 57% (117 of 205), 75% (248 of 330), and 68% (365 of 535), respectively. Finally, if > or = 1.0 mm of upsloping ST-segment depression is considered abnormal, these values were 71% (142 of 199), 56% (187 of 336), 49% (142 of 291), 77% (187 of 244), and 61% (329 of 535), respectively. Thus, if upsloping ST-segment depression is added to the criteria for a positive exercise test result, sensitivity for detection of ischemia is increased but at the expense of a fall in specificity and a significant decrease in the positive predictive value of the test.
通过将可逆性铊-201（²⁰¹Tl）缺损作为缺血的标准，来确定在平板运动试验期间观察到的不同程度的上斜型ST段压低对运动ST段反应检测缺血准确性的补充价值。研究了一组199例连续患者（168例男性），这些患者在定量平面灌注成像上有≥1个可逆性²⁰¹Tl缺损，以及一组366例²⁰¹Tl扫描正常且达到年龄预测最大心率≥85%的正常患者。将J点后0.08秒时低于基线的持续ST段压低≥1.0、≥1.5和≥2.0mm的上斜型ST段压低进行亚分类。如果仅将≥1.0mm的水平或下斜型ST段压低指定为异常，而将所有上斜型反应指定为正常，则运动心电图的敏感性、特异性、阳性预测值、阴性预测值和准确性分别为49%（199例中的98例）、84%（336例中的281例）、64%（153例中的98例）、74%（382例中的281例）和71%（535例中的379例）。如果除了≥1.0mm的水平或下斜型ST段压低外，还将≥2.0mm的上斜型ST段压低视为异常，则这些值分别为52%（199例中的104例）、81%（336例中的272例）、62%（168例中的104例）、74%（367例中的272例）和70%（535例中的376例）。如果将≥1.5mm的上斜型ST段压低视为异常反应，则这些值分别为59%（199例中的117例）、74%（336例中的248例）、57%（205例中的117例）、75%（330例中的248例）和68%（535例中的365例）。最后，如果将≥1.0mm的上斜型ST段压低视为异常，则这些值分别为71%（199例中的142例）、56%（336例中的187例）、49%（291例中的142例）、77%（244例中的187例）和61%（535例中的329例）。因此，如果将上斜型ST段压低添加到运动试验阳性结果的标准中，检测缺血的敏感性会增加，但代价是特异性下降和试验的阳性预测值显著降低。
