Vaitkus P T, Kindwall K E, Marchlinski F E, Miller J M, Buxton A E, Josephson M E
Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia 19104.
Circulation. 1991 Aug;84(2):672-8. doi: 10.1161/01.cir.84.2.672.
Many studies have combined patients with hemodynamically well-tolerated ventricular tachycardia (VT) and those with cardiac arrest (CA) as a single, homogenous group. Recent studies suggest that these two groups have different electrophysiological substrates and responses to therapy. Most of these studies, however, enrolled patients with a variety of cardiac diagnoses.
We used signal-averaged electrocardiography (SAECG) and endocardial catheter mapping to define the electrophysiological substrate in patients with coronary artery disease and VT or CA and correlate the results of the two methods. We also examined the usefulness of SAECG in CA patients to differentiate those with inducible arrhythmias from those who are noninducible. VT patients were more likely to have had a prior myocardial infarction (p = 0.0005) and to have inducible arrhythmias (p = 0.0001) than were CA patients. The induced arrhythmias in patients who presented with VT was VT in more than 90% of cases, whereas in CA patients, polymorphic ventricular tachycardia (PMVT) accounted for one third of induced arrhythmias. Mean filtered QRS duration was longer (135 versus 120 msec) and the terminal QRS voltage was smaller (20 versus 34 microV) in VT than in CA patients (p less than 0.01). Sixty-three percent of CA patients and 87% of VT patients had abnormal SAECG (p = 0.001). VT patients had more extensive endocardial abnormalities and more abnormal (53% versus 40%, p = 0.002), fractionated (8% versus 3%, p = 0.02), late (17% versus 8%, p = 0.0003), and late abnormal or fractionated (14% versus 4%, p = 0.0001) sites than CA patients. VT patients had a greater duration of the longest electrogram (129 versus 109 msec, p = 0.0006) and total endocardial activation time (68 versus 54 msec, p = 0.009). Among CA patients, those with induced VT had more extensive substrate than did those with induced PMVT and were similar to VT patients with induced VT. Among CA patients, the trend for more patients with inducible VT (77%) or PMVT (55%) than noninducible patients (47%) to have an abnormal SAECG did not reach statistical significance (p = 0.14). The positive and negative predictive values of an abnormal SAECG were 77% and 44%, respectively.
VT patients have more extensive endocardial substrate than CA patients, which translates into greater and more frequent SAECG abnormalities. Among CA patients, there are significant differences in substrate between patients with induced VT and those with induced PMVT. SAECG is not useful in differentiating CA patients who have inducible VT or PMVT from those who do not.
许多研究将血流动力学耐受性良好的室性心动过速（VT）患者和心脏骤停（CA）患者合并为一个同质组。近期研究表明，这两组患者具有不同的电生理基质和对治疗的反应。然而，这些研究大多纳入了患有各种心脏疾病诊断的患者。
我们使用信号平均心电图（SAECG）和心内膜导管标测来确定冠心病合并VT或CA患者的电生理基质，并将两种方法的结果进行关联。我们还研究了SAECG在CA患者中区分可诱发性心律失常患者与不可诱发性心律失常患者的效用。与CA患者相比，VT患者更可能有既往心肌梗死史（p = 0.0005）且有可诱发性心律失常（p = 0.0001）。表现为VT的患者中，超过90%的病例诱发的心律失常为VT，而在CA患者中，多形性室性心动过速（PMVT）占诱发心律失常的三分之一。VT患者的平均滤波QRS时限更长（135对120毫秒），终末QRS电压更小（20对34微伏），而CA患者则相反（p < 0.01）。63%的CA患者和87%的VT患者SAECG异常（p = 0.001）。VT患者的心内膜异常更广泛，异常（53%对40%，p = 0.002）、碎裂（8%对3%，p = 0.02）、延迟（17%对8%，p = 0.0003）以及延迟异常或碎裂（14%对4%，p = 0.0001）部位比CA患者更多。VT患者最长心电图时限更长（129对109毫秒，p = 0.0006），总心内膜激动时间更长（68对54毫秒，p = 0.009）。在CA患者中，诱发性VT患者的基质比诱发性PMVT患者更广泛，且与诱发性VT的VT患者相似。在CA患者中，可诱发性VT（77%）或PMVT（55%）患者比不可诱发性患者（47%）有更多异常SAECG的趋势未达到统计学意义（p = 0.14）。SAECG异常的阳性和阴性预测值分别为77%和44%。
VT患者的心内膜基质比CA患者更广泛，这导致SAECG异常更严重且更频繁。在CA患者中，诱发性VT患者和诱发性PMVT患者的基质存在显著差异。SAECG对于区分有可诱发性VT或PMVT的CA患者与无此情况的患者并无用处。
