Morgan C D, Gent M, Daly P A, Baigrie R S, Haq A, Roberts R S, Armstrong P W
Sunnybrook Health Science Centre, University of Toronto, Toronto Hospital, Ontario.
Can J Cardiol. 1994 Nov;10(9):897-904.
To determine the influence of timing, infarct location and thrombolytic therapy on the electrocardiographic (ECG) response to exercise testing following acute myocardial infarction.
Maximal treadmill exercise testing was performed on postinfarction day 8 and repeated on day 90 as part of a previously reported double-blind, placebo controlled study of recombinant tissue plasminogen activator (rt-PA) in acute myocardial infarction in which left ventricular function was the primary end-point. Patients were systematically evaluated for left ventricular function, myocardial perfusion and coronary anatomy.
Ten collaborating community and academic hospitals.
One hundred and fifteen patients, aged 20 to 75 years, with ischemic chest pain 30 mins or longer and ST elevation on ECG. Patients with cardiogenic shock, left bundle branch block, prior aortocoronary bypass surgery, recent percutaneous transluminal coronary angioplasty or standard contraindications to thrombolytic therapy were excluded.
The analysis is confined to the 70 patients who underwent both exercise tests without intercurrent coronary revascularization. Peak rate-pressure product was greater on day 90 than on day 8 (mean difference +/- SE 2.2 +/- 0.6 x 10(3), P = 0.001), whereas 65% of patients had 1 mm or greater of exercise-induced ST shift on day 8 compared with 47% on day 90 (P = 0.025). Patients following anterior compared with inferior infarction were more likely to have exercise-induced ST elevation (54% versus 21%, P = 0.012) but less likely to have ST depression (29% versus 63%, P = 0.017) on day 8; results were directionally similar on day 90. Treatment with rt-PA, compared with placebo, did not influence exercise performance, the ECG response to exercise or the extent of inducible ischemia on thallium scintigraphy.
Timing and infarct location are important modifiers of the ECG response to exercise testing following myocardial infarction. Thrombolytic therapy in these uncomplicated patients did not influence inducible ischemia.
确定时间、梗死部位和溶栓治疗对急性心肌梗死后运动试验心电图（ECG）反应的影响。
作为先前报道的一项关于重组组织型纤溶酶原激活剂（rt-PA）治疗急性心肌梗死的双盲、安慰剂对照研究的一部分，在心肌梗死后第8天进行最大运动平板试验，并于第90天重复进行，该研究以左心室功能作为主要终点。对患者进行左心室功能、心肌灌注和冠状动脉解剖的系统评估。
十家合作的社区医院和学术医院。
115例年龄在20至75岁之间，有30分钟或更长时间缺血性胸痛且心电图ST段抬高的患者。排除心源性休克、左束支传导阻滞、既往接受过主动脉冠状动脉搭桥手术、近期接受过经皮腔内冠状动脉成形术或有溶栓治疗标准禁忌证的患者。
分析限于70例未同时进行冠状动脉血运重建的情况下接受了两次运动试验的患者。第90天的峰值心率血压乘积高于第8天（平均差值±标准误 2.2±0.6×10³，P = 0.001），而第8天65%的患者运动诱发的ST段偏移≥1mm，第90天为47%（P = 0.025）。梗死位于前壁的患者与下壁梗死患者相比，在第8天更易出现运动诱发的ST段抬高（54%对21%，P = 0.012），但较少出现ST段压低（29%对63%，P = 0.017）；第90天结果在方向上相似。与安慰剂相比，rt-PA治疗不影响运动表现、运动试验的心电图反应或铊闪烁显像上可诱导缺血的程度。
时间和梗死部位是心肌梗死后运动试验心电图反应的重要调节因素。在这些无并发症的患者中，溶栓治疗不影响可诱导的缺血。
