Introduction:
In inferior wall acute myocardial infarction (IWMI), ST-segment elevation in leads V5-6 (STE V5-6) is often observed, but its prognostic impact is unclear.
Methods:
We examined admission ECGs in 361 patients with a first IWMI who had TIMI 3 flow of the right coronary artery (RCA) or left circumflex artery (LCX) by reperfusion therapy within 6 hours after symptom onset. Patients were divided according to the presence (n=77) or absence (n=284) of STE V5-6 >2 mm, and the former was subdivided into the 2 groups according to the degree of STE in leads III and V6: STE:III>V6 (n=53) and STE:III≤V6 (n=24). The perfusion territory of the culprit artery was assessed by angiographic distribution score, and mega-artery was defined as a score ≥0.7.
Results:
Age, sex, time to admission, reperfusion therapy, or time to reperfusion was similar in the 3 groups. STE V5-6 was associated with mega-artery occlusion, larger infarction, and in-hospital adverse events (death, reinfarction, or heart failure). RCA occlusion was most common in STE V5-6 with STE:III>V6, whereas LCX occlusion, especially proximal LCX occlusion, was most common in STE V5-6 with STE:III≤V6. In multivariate analysis, STE V5-6 with STE:III>V6 (OR 2.90, 95%CI 1.10-7.02, p<0.01) and that with STE:III≤V6 (OR 3.63, 95%CI 1.58-8.96, p<0.01) were independent predictors of in-hospital adverse events.
Conclusions:
In reperfused IWMI, ST-segment elevation in leads V5-6 on admission ECG strongly predicts in-hospital adverse outcomes; furthermore, comparing the degree of ST-segment elevation in leads III and V6 is useful for predicting the culprit artery (i.e., RCA or LCX).
Implications of the absence of st-segment elevation in lead V4Rin patients who have inferior wall acute myocardial infarction with right ventricular involvement
