急性前壁心肌梗死早期T波倒置程度的临床意义

Clinical significance of varying degrees of the early maximal negative T wave in acute anterior myocardial infarction

目的 探讨心肌梗死早期心电图中最大倒置T波 (maximalnegativeTwave ;NTmax)的临床意义。方法 以初发急性前壁心肌梗死 (AMI) 10h以内来院就诊的 80例患者作为对象。根据NTmax深度分为三组 :(1)深倒置T波 (DNT)组 :NTmax≥ 10mm ;(2 )中度倒置T波 (INT)组 :4mm≥NTmax <10mm ;(3)浅倒置T波 (SNT)组 :NTmax <4mm。根据铊2 0 1心肌同位素显像和锝99心室腔同位素造影分别求出心肌灌注指数和左室射血分数 (LVEF) ,将肌酸激酶最高值 (CKmax)、心肌灌注指数和LVEF作为判断心肌梗死严重程度的指标 ,分析了NTmax与心肌梗死面积、左室功能状况的关系。结果 NTmax出现在发病后 4～ 10 2 (4 7.2± 2 1.4)h ,NTmax与CKmax呈逆相关 (r =0 .416 ,P <0 .0 0 5 ) ,与左室射血分数 (r=0 .5 6 4,P <0 .0 0 3)呈正相关。DNT组与其他二组比较 ,V1 V4 导联降低的R波迅速恢复 ,抬高的ST段恢复得早 ,T波早期倒置。

Objective To evaluate the clinical significance of the early maximal negative T wave (NTmax) on electrocardiography in acute anterior myocardial infarction. Methods The early maximal negative T wave on electrocardiaogram was evaluated in 80 patients with initial acute anterior myocardial infarction (MI) admitted with in 10 hours after the onset. Patients were divided into 3 groups based on NTmax, the deep negative T (DNT) group (NTmax ≥10mm), intermediate negative T(INT) group (4 mm ≤NTmax <10 mm) and shallow negative T (SNT) group (NTmax<10 mm). Total myocardial perfusion index and left ventricular ejection fraction (LVEF) were obtained by thallium 201 single photon emission computed tomography myocardial scintigraphy and technetium 99m ventricular scintigraphy. The relationship among the NTmax, the area of MI and function of left ventricle was assessed by the parameters of maximal creatine phosphokinase (CKmax), total myocardial perfusion index and LVEF. Results The amplitude of NTmax was observed from 4 to 102 hours after the onset(mean 47.2±21.4). NTmax was inverse correlated with CKmax( r =-0.416, P <0.005), and significantly correlated with LVEF ( r =0.564, P <0.003). Compared with the other two groups, the DNT group revealed smaller CKmax ( P <0.05), lower LVEF and myocardial perfusion index ( P <0.05), respectively. Serial electrocardiography showed the relatively early reappear of R waves in leads V 1 V 4, normalization of ST segment, and appearance of T wave inversion ( P <0.05, respectively) in DNT group. Conclusion NTmax probably is a clinically simple and useful parameter to estimate the severity of acute anterior myocardial infarction.