Dzavik V, Beanlands D S, Leddy D, Davies R F, Kimber S
University of Alberta Hospitals, Edmonton.
Can J Cardiol. 1995 May;11(5):378-84.
Early infarct-related artery patency associated with thrombolytic therapy decreases the incidence of signal-averaged electrocardiogram (SAECG) derived late potentials following acute Q wave myocardial infarction. The purpose of this prospective study was to follow the development of SAECG abnormalities in patients with persistent occlusion of the infarct-related artery, and to compare the course of those who subsequently had successful late percutaneous transluminal coronary angioplasty and coronary artery bypass grafting surgery with the course of those who were not revascularized.
Baseline (24 +/- 25 days after myocardial infarction) SAECG studies were acquired from 39 patients just before revascularization of the infarct-related artery (group 1) and from 32 nonrevascularized patients (group 2). Late potentials were found in 19 group 1 patients and in 13 group 2 patients (not significant). Follow-up studies were done 103 +/- 63 days after baseline acquisition.
There were no differences between the two groups in the change in filtered QRS (fQRS), in low amplitude signal duration under 40 microV (LAS), or in the root mean square voltage of the last 40 ms (RMS). No difference was found in the frequency of resolution of late potentials (21.0% in group 1 versus 38.5% in group 2). Patients in whom late potential resolution occurred had less abnormal LAS than patients with persistent late potentials, and less abnormal RMS. In addition, the magnitude of change in the fQRS, LAS and RMS was significantly greater in patients with late potential resolution than in those with late potential persistence.
Late revascularization of an occluded infarct-related artery does not appear to enhance resolution of late potentials compared with conservative medical therapy. Resolution occurs in patients with less severe SAECG abnormalities. This may reflect a difference in arrhythmogenic substrate.
溶栓治疗相关的早期梗死相关动脉通畅可降低急性Q波心肌梗死后信号平均心电图（SAECG）衍生的晚电位发生率。本前瞻性研究的目的是追踪梗死相关动脉持续闭塞患者SAECG异常的发展情况，并比较随后成功进行晚期经皮腔内冠状动脉成形术和冠状动脉旁路移植术的患者与未进行血运重建的患者的病程。
在梗死相关动脉血运重建前（第1组），从39例患者中获取基线（心肌梗死后24±25天）SAECG研究数据，并从32例未进行血运重建的患者（第2组）中获取数据。第1组19例患者和第2组13例患者发现有晚电位（无显著性差异）。在基线采集后103±63天进行随访研究。
两组在滤波QRS波（fQRS）、40微伏以下低振幅信号持续时间（LAS）或最后40毫秒的均方根电压（RMS）变化方面无差异。晚电位消失频率无差异（第1组为21.0%，第2组为38.5%）。晚电位消失的患者比持续存在晚电位的患者LAS异常程度更低，RMS异常程度也更低。此外，晚电位消失的患者fQRS、LAS和RMS的变化幅度明显大于晚电位持续的患者。
与保守药物治疗相比，梗死相关动脉闭塞的晚期血运重建似乎并未增强晚电位的消失。SAECG异常较轻的患者会出现晚电位消失。这可能反映了致心律失常基质的差异。
