Echocardiographic comparison of regional wall motion abnormality between patients with acute anteroseptal and acute extensive anteior ST segment elevation myocardial infarction

Abstract

Post myocardial infarction (MI) short and long term clinical outcome is largely determined by the size of the infarcted area. It is generally assumed that as the lead involvement in electrocardiography (ECG) is less in anteroseptal ST segment elevation myocardial infarction (AS-STEMI), where ST segment elevation (STE) is limited to leads V₁ to V₃, myocardial damage is likely to be less; and in extensive anterior STEMI (EA-STEMI), as theSTE extends further upto V6, the myocardial damage is likely to be more. This study was intended to compare regional wall motion abnormality (RWMA) between acute anteroseptal STEMI and acute extensive anterior STEMI patients. 90 patients with AS-STEMI and 106 patients with EA-STEMI, admitted in between October 2012 and September 2013, were included. For each patient, a transthoracic echocardiogram (TTE) was performed within 24-48 hours of MI and was interpreted by an independent investigator blinded to the patient's ECG data. No differences were observed between the two groups in baseline characteristics; except AS-STEMI group had more patients with diabetes and EA-STEMI group had more patients with family history of coronary artery disease. Distribution, extent of wall motion abnormalities and mean number of total involved segments were similar between patients with AS-STEMI and those with EA-STEMI (p>0.05). Regarding regional dysfunction, the apical septal (99.1% vs. 92.2%, p<0.05) and apical (76.4% vs. 60.0%, p<0.05) segments were the only two segments that were affected significantly more in patients with EA-STEMI than in patients with AS-STEMI. So, the term AS-STEMI may be a misnomer, as it implies that only the anteroseptal segments of the left ventricle are involved. This study shows that regional dysfunction in patients with AS-STEMI extends beyond the anteroseptal region. So, any patients with anterior wall involvement, either anteroseptal or extensive anterior STEMI, should be treated with equal importance.