Diagnostic implication of hyperkinesia of the inferior septum for prediction of culprit artery in patients with inferior wall myocardial infarction

Abstract

Background: Inferior wall MI is known for its diversity in clinical presentation due to substantial difference in clinical features in case of LCX and RCA occlusion. Hence prediction of culprit vessel of occlusion is very essential for anticipation of infarct related complications. However superposition of area of blood supply between LCX and RCA in inferior wall and adjacent lateral wall is a hindrance in prediction of culprit artery in inferior wall MI.Whereas adjacent inferior septum is supplied by both RCA &LAD but not supplied by LCX, so in case of LCX occlusion, adjacent myocardial fibres of inferior septum contracts vigorously to minimize the LV dysfunction and present as compensatory hyperkinesia. Aim: To study regional wall motion abnormality (RWMA), more specifically hyperkinesia in inferior septum for prediction of culprit artery in patients with acute inferior wall MI. Materials and Methods:A cross sectional study was conducted enrolling a total of 1429 patients with acute Inferior wall STEMI. All the patients were subjected to echocardiography to study RWMA in inferior septum. Taking into consideration of the inclusion & exclusion criteria total of 884 patients with single vessel disease as confirmed by angiography were finalised as the study participants.Results:Out of 884 patients, RCA was found as culprit artery in 645(73%) patients (group A) and LCX as culprit artery in 239(27.0%) patients (group B).While studying wall motion abnormality in the inferior septum, hyperkinesia was found in 87.4% cases in LCX disease as compared to 6.04% cases with in RCA disease with and the difference was found statistically highly significant.Conclusion: Hyperkinetic inferior septum can be an important diagnostic marker for distinguishing LCX lesion from RCA lesion in inferior wall MI.