急性下壁心肌梗死累及右心室或侧后壁时对心电图胸前导联ST段影响的研究

Factors that affect the direction and magnitude of precordial ST segment deviations during inferior wall acute myocardial infarction associated with right ventricular or lateralposterior infarction

目的 :探讨急性下壁心肌梗死累及右心室或侧后壁时 ,对心电图胸前导联 ST段改变的影响及其临床意义。方法 :对 1 1 8例首次急性下壁心肌梗死患者的心电图进行比较分析。结果 :急性下壁心肌梗死时心电图下壁导联 ST段抬高幅度与胸前导联 ST段改变均呈负相关 (P均 <0 .0 1 )。在 1 6例同时合并右室梗死的患者中 ,胸前导联 ST段改变幅度〔V2 导联为 (0 .6 3± 1 .82 ) mm〕及与下壁导联 ST段抬高的比值 (V2 / a VF为0 .84± 1 .6 1 )均高于单纯下壁梗死组〔V2 导联为 (0 .35± 1 .6 5 ) m m,V2 / a VF为 0 .2 9± 1 .2 8〕;而 38例同时合并侧后壁梗死的患者胸前导联 ST段压低的幅度〔V2 导联为 (- 1 .2 0± 1 .5 2 ) mm〕及与下壁导联 ST段抬高的比值 (V2 / a VF为 - 0 .33± 1 .1 5 )均低于单纯下壁梗死组 ,且差异具有显著性意义 (P<0 .0 1或 P<0 .0 5 )。如去掉累及右室梗死和侧后壁梗死的病例 ,可使急性下壁心肌梗死心电图下壁导联与胸前导联 ST段的相关性显著提高 (r=- 0 .797,P<0 .0 1 )。结论 :急性下壁心肌梗死患者同时合并右室梗死可使心电图胸前导联 ST段趋于抬高 ;而合并侧后壁梗死则使胸前导联 ST段进一步降低 ,二者呈相反关系。

Objective:To evaluate the clinical significance and factors that affect the direction and magnitude of precordial ST segment deviations during inferior wall acute myocardial infarction associated with right ventricular or lateralposterior infarction.Methods:Characteristics of electrocardiogram were analyzed in 118 patients with acute inferior wall myocardial infarction.Results:The magnitude of ST segment elevation in inferior wall leads was significantly negatively correlated with that of precordial leads in acute inferior wall myocardial infarction (all P <0 01).The magnitude of ST segment of lead V 2 (0 63±1 82)mm and V 2/aVF ratio 0 84±1 61 in 16 cases associated with right ventricular infarction were significantly higher than that of pure inferior wall myocardial infarction group 〔V 2:(0 35±1 65)mm,V 2/aVF:0 29±1 28〕,while the ST segment magnitude of lead V 2(-1 20±1 52)mm and V 2/aVF ratio -0 33±1 15 in 38 cases associated with lateralposterior wall infarction were signifcantly lower than that of pure inferior wall infarction group ( P <0 01 or P <0 05 ).The ST segment correlation coefficient between inferior leads and precordial would increase significantly in acute inferior wall infarction ( r =-0 797, P <0 01),if the cases associated with right ventricular and lateralposterior wall infarction were excluded.Conclusions:In acute inferior wall myocardial infarction,the ST segment of the precordial lead tends to be elevated in the cases associated with right ventricular infarction and lowered in the case associated with lateralposterior wall infarction.