Institute of Cardiology and Center of Excellence on Aging, "G. d'Annunzio" University-Chieti Italy, Italy.
Int J Cardiol. 2013 Sep 30;168(2):1274-9. doi: 10.1016/j.ijcard.2012.12.007. Epub 2012 Dec 21.
Because ST segment depression has limited diagnostic performance at exercise electrocardiography (ECG), ST segment depression/heart rate (ST/HR) hysteresis and cardiopulmonary exercise test (CPET)-derived parameters have been proposed as alternatives to diagnose exercise-induced myocardial ischemia. We compared the diagnostic performance of such parameters.
We studied 56 subjects (45 men, 11 women, age 59.7 ± 13.6 years) referred for suspected exercise-induced myocardial ischemia with an equivocal ECG exercise test. All subjects serially underwent CPET and a myocardial single-photon emission computerized tomography (SPECT) perfusion imaging (as the gold standard for ischemia). Maximum ST depression at peak exercise (ST-max), the ST/HR hysteresis, ΔVO2/ΔWR b-b1 slope, ΔVO2/ΔWR (aa1-bb1), VO2/HR flattening duration and other CPET parameters were derived in all subjects.
On the basis of SPECT, 23 subjects (41%) were considered ischemic and 33 subjects (59%) non-ischemic. ST/HR hysteresis was higher (0.026 mV; 95% CI: 0.003 to 0.049 vs -0.016 mV; 95% CI: -0.031 to -0.001 mV) and ST-max was lower (-0.105 mV; 95% CI: -0.158 to -0.052 vs 0.032 mV; 95% CI: -0.001 to -0.066 mV) in ischemic vs non-ischemic subjects (P=0.004 and P=0.001, respectively). Among CPET parameters, ΔVO2/ΔWR b-b(1) slope was lower (9.4 ± 3.8) and ΔVO2/ΔWR (aa(1)-bb(1)) was higher (2.1 ± 2.6) in ischemic vs non-ischemic subjects (11.4 ± 2.3, P=0.005, and 1.1 ± 1.5, P=0.001, respectively). The ST/HR hysteresis had the highest area under the curve value, better (P<0.05) than any other parameters tested, thus showing the highest overall diagnostic performance.
The ST/HR hysteresis is superior to CPET-derived parameters for detecting exercise-induced myocardial ischemia in patients with equivocal ECG exercise test results.
由于 ST 段压低在运动心电图（ECG）中的诊断性能有限，因此已经提出了 ST 段压低/心率（ST/HR）滞后和心肺运动试验（CPET）衍生参数作为诊断运动诱导心肌缺血的替代方法。我们比较了这些参数的诊断性能。
我们研究了 56 名（45 名男性，11 名女性，年龄 59.7±13.6 岁）因可疑运动诱导心肌缺血而行心电图运动试验结果不确定的患者。所有患者均连续进行 CPET 和心肌单光子发射计算机断层扫描（SPECT）灌注成像（作为缺血的金标准）。在所有患者中得出最大 ST 段压低（ST-max）、ST/HR 滞后、Δ VO2/Δ WR b-b1 斜率、Δ VO2/Δ WR（aa1-bb1）、VO2/HR 平坦持续时间和其他 CPET 参数。
根据 SPECT，23 名患者（41%）被认为是缺血性的，33 名患者（59%）是非缺血性的。ST/HR 滞后较高（0.026 mV；95%CI：0.003 至 0.049 比-0.016 mV；95%CI：-0.031 至-0.001 mV），ST-max 较低（-0.105 mV；95%CI：-0.158 至-0.052 比 0.032 mV；95%CI：-0.001 至-0.066 mV）在缺血性与非缺血性患者中（P=0.004 和 P=0.001）。在 CPET 参数中，Δ VO2/Δ WR b-b（1）斜率较低（9.4±3.8），Δ VO2/Δ WR（aa（1）-bb（1））较高（2.1±2.6）在缺血性与非缺血性患者中（11.4±2.3，P=0.005 和 1.1±1.5，P=0.001）。ST/HR 滞后的曲线下面积值最高，优于任何其他测试的参数（P<0.05），因此显示出最高的整体诊断性能。
在心电图运动试验结果不确定的患者中，ST/HR 滞后对于检测运动诱导的心肌缺血优于 CPET 衍生参数。
