ABSTRACT
Objective To investigate whether terminal QRS distortion on the electrocardiogram in acute inferior myocardial infarction could be as a standard for the infarct-related artery,through comparing to coronary angiography.Methods Fifty-seven patients with acute inferior myocardial infarction were enrolled,among which,the right coronary artery (RCA) occlusion (RCA occlusion group) was present in 29 cases,and left circumflex coronary artery (LCX) occlusion (LCX occlusion group) was in 28 cases.The changes of electrocardiogram was analyzed in 12 hours after the acute episode.Results The incidence of terminal QRS distortion in leads Ⅱ,Ⅲ,aVF in RCA occlusion group was 44.8％(13/29) and 39.3％(11/28)in LCX occlusion group,and there was no significant difference (P ＞ 0.05).The incidence of terminal QRS distortion in leads V4R-V5R in RCA occlusion group was 17.2％(5/29) and 7.1％(2/28) in LCX occlusion group,and there was no significant difference (P ＞ 0.05).The incidence of terminal QRS distortion in leads V7-V9 in RCA occlusion group was 6.9％(2/29),which was lower than that in LCX occlusion group[53.6％(15/28)],and there was significant difference (P ＜ 0.05).For identifying LCX as the infarct-related artery of acute inferior myocardial infarction,the sensitivity,specificity,positive and negative value in terminal QRS distortion in leads V7-V9 were 53.6％ (15/28),93.1％ (27/29),88.2％ (15/17),67.5％ (27/40).The area under curve of terminal QRS distortion in leads V7-V9 in identifying LCX as the infarct-related artery of acute inferior myocardial infarction was 0.733 (95％ CI 0.599-0.868).Conclusion Terminal QRS distortion in leads V7-V9 may be of diagnostic value in identifying the infarct-related artery in acute inferior myocardial infarction.