急性下壁心肌梗死邻近部位受累时胸前对应导联ST段改变机制及临床意义的研究

目的研究急性下壁心肌梗死(AIMI)累及邻近部位时，心电图胸前对应导联ST段改变的影响因素及临床意义。方法对118例首次AIMI患者的心电图和临床资料进行比较分析。结果(1)AIMI时心电图下壁各导联(Ⅱ、Ⅲ和aVF)ST段抬高幅度与胸前对应导联ST段改变的相关指标均呈负相关(均P＜0.01)。(2)累及右室(16例)的患者胸前对应导联ST段的改变幅度[V2(0.63±1.82)mm]及与下壁导联ST段抬高的比值(V2/aVF0.84±1.61)，均高于64例单纯下壁梗死组[V2(0.35±1.65)mm，V2/aVF0.29±1.28]；差异尚无显著性(均P＞0.05)。(3)累及侧后壁的患者(38例)胸前对应导联ST段压低幅度[V2(-1.20±1.52)mm]及与下壁导联ST段抬高的比值[V2/aVF(-0.33±1.15)mm]均低于单纯下壁组，且差异均具有显著性意义(P＜0.05)。(4)在除去累及邻近部位梗死的病例，单纯AIMI心电图下壁导联与胸前对应导联ST段改变呈负相关(r=-0.797，P＜0.01)。结论当AIMI累及右室时可使心电图胸前对应导联ST段趋于抬高，而累及侧后壁时则使胸前对应导联ST段进一步降低，故胸前对应导联ST段的改变方向与AIMI累及邻近部位关系密切。

Study on Mechanism and Clinical Significance of the Precordial ST Segment Deviations in Acute Inferior Myocardial Infarction Involving Adjacent Area

Objective:To study the mechanism and clinical significance of the precordial ST segment deviations in acute inferiorwall myocardial infarction (AIMI) involving adjacent area. Methods: Characteristics of electrocardiogram were analyzed in118 patients with AIMI. Results: (1)The magnitude of ST segment elevation of inferior wall leads (Ⅱ, Ⅲ and aVF) wassignificantly negatively correlated with that of precordial leads (P＜0.01). (2)The changed magnitude of ST segment oflead V2 (0.63±1.82 mm) and V2/aVF ratio (0.84±1.61) in 16 cases associated with right ventricular infarction weresignificantly higher than those of only inferior wall myocardial infarction group (V2:0.35±1.65 mm,V2/aVF ratio:0.29±1.28)(P＞0.05 and P＞0.05). (3)The magnitude of ST segment fall of lead V2(-1.20±1.52 mm) and V2/aVFratio (-0.33±1.15) in 38 cases associated with lateral-posterior wall in farction were higher than those of only inferiorwall infarction group (P＜0.05). (4)If the cases associated with right ventricular and lateral-posterior wall infarction werenot included, the ST segment correlation coefficient between inferior and precordial leads would significantly increase inAIMI (r =-0.797, P＜0.01). Conclusion:The directions of ST segment deviations of precordial leads elevate in casesassociated with right ventricular infarction and fall in eases associated with lateral-posterior wall infarction in AIMI.