Bogaty P, Guimond J, Robitaille N M, Rousseau L, Simard S, Rouleau J R, Dagenais G R
Québec Heart Institute/Laval Hospital, Ste-Foy, Canada.
J Am Coll Cardiol. 1997 Jun;29(7):1497-504. doi: 10.1016/s0735-1097(97)00091-0.
We explored how the exercise electrocardiographic (ECG) indexes generally presumed to signify severe ischemic heart disease (IHD) correlate with coronary angiographic and scintigraphic myocardial perfusion findings.
In exercise testing, it is generally assumed that the early onset of ST segment depression and its occurrence at a low rate-pressure product (ischemic threshold); the amount of maximal ST segment depression; and a horizontal or downsloping ST segment and its prolonged recovery after exercise signify more severe IHD. However, the relation of these indexes to coronary angiographic and exercise myocardial perfusion findings in patients with IHD is unclear.
We prospectively carried out a symptom-limited 12-lead Bruce protocol thallium-201 single-photon emission computed tomographic (SPECT) exercise test in 66 consecutive subjects with stable angina, > or = 70% stenosis of at least one coronary artery, normal rest ECG and left ventricular wall motion and a prior positive exercise ECG. The above ECG indexes, vessel disease (VD), a VD score and the quantitative thallium-SPECT measures of the extent, maximal deficit and redistribution gradient of the perfusion abnormality were characterized.
Maximal ST segment depression could not differentiate the number of diseased vessels; was not related to VD score, maximal thallium deficit or redistribution gradient; but was related to the extent of perfusion abnormality (r = 0.29, 95% confidence interval [CI] 0.08 to 0.52, p = 0.02). Time of onset of ST segment depression correlated inversely only with VD (r = -0.22, 95% CI -0.44 to -0.05, p < 0.05), whereas the ischemic threshold had low inverse correlation only with VD score (r = -0.25, 95% CI -0.47 to -0.01, p < 0.05) and the redistribution gradient (r = -0.33, 95% CI -0.53 to -0.10, p < 0.01). A horizontal or downsloping compared with an upsloping ST segment did not demonstrate more severe angiographic and scintigraphic disease. Recovery time did not correlate with angiographic and scintigraphic findings, and correlations between angiographic and scintigraphic findings were also low or absent.
In this homogeneous study group, the exercise ECG indexes did not necessarily signify more severe IHD by angiographic and scintigraphic criteria. Lack of concordance between the exercise ECG, angiography and myocardial scintigraphy suggests that these diagnostic modalities examine different facets of myocardial ischemia, underscoring the need for caution in the interpretation of their results.
我们探讨了一般认为表示严重缺血性心脏病（IHD）的运动心电图（ECG）指标与冠状动脉造影及心肌灌注闪烁显像结果之间的相关性。
在运动试验中，一般认为ST段压低的早期出现及其在低心率 - 血压乘积（缺血阈值）时的发生；最大ST段压低的程度；以及水平或下斜型ST段及其运动后恢复延长表示更严重的IHD。然而，这些指标与IHD患者的冠状动脉造影及运动心肌灌注结果之间的关系尚不清楚。
我们对66例连续的稳定型心绞痛患者进行了前瞻性症状限制性12导联Bruce方案铊 - 201单光子发射计算机断层扫描（SPECT）运动试验，这些患者至少有一支冠状动脉狭窄≥70%，静息心电图和左心室壁运动正常，且运动心电图先前呈阳性。对上述ECG指标、血管疾病（VD）、VD评分以及灌注异常的范围、最大缺损和再分布梯度的定量铊 - SPECT测量进行了特征分析。
最大ST段压低不能区分病变血管的数量；与VD评分、最大铊缺损或再分布梯度无关；但与灌注异常的范围相关（r = 0.29，95%置信区间[CI] 0.08至0.52，p = 0.02）。ST段压低的起始时间仅与VD呈负相关（r = -0.22，95% CI -0.44至 -0.05，p < 0.05），而缺血阈值仅与VD评分（r = -0.25，95% CI -0.47至 -0.01，p < 0.05）和再分布梯度（r = -0.33，95% CI -0.53至 -0.10，p < 0.01）呈低负相关。与上斜型ST段相比，水平或下斜型ST段并未显示出更严重的血管造影和闪烁显像疾病。恢复时间与血管造影和闪烁显像结果无关，血管造影和闪烁显像结果之间的相关性也很低或不存在。
在这个同质的研究组中，根据血管造影和闪烁显像标准，运动心电图指标不一定表示更严重的IHD。运动心电图、血管造影和心肌闪烁显像之间缺乏一致性表明这些诊断方式检查了心肌缺血的不同方面，强调在解释其结果时需要谨慎。
