Comparison of Left Ventricular Ejection Fraction in Patients of Acute Inferior Wall Myocardial infarction with or without Reciprocal ECG Changes

Objective: To determine the frequency of decrease in left ventricular ejection fraction in patients of acute inferior wall MI and to compare the decrease in left ventricular ejection fraction in patients of acute inferior myocardial infarction presenting with or without precordial lead reciprocal changes. To investigate the accuracy of the 12-lead ECG in localizing the site of coronary artery narrowing. Study Design: Cross-sectionalstudy. Setting: Study was carried out at Department of Cardiology, Pakistan Institute of Medical Sciences, Islamabad and Punjab institute of cardiology Lahore, From March 2010 till August 2011. Materials and Methods: Patients with chest pain had their ECG analysis done at the time of admission. Those with acute inferior MI subsequently underwent ECG analysis for determination of reciprocal ST changes. They then had echocardiography done. EF was compared between patients with or without reciprocal changes. Results:Our study included 80 patients with acute inferior wall infarction with a mean age of 54.475.65 years. 52 (65%) were males.55 (68.7%) patients had reciprocal ST segment depression. 38 (69%) had RSTD in apicolateral leads (1, avL,V4,V5,V6) and 17 (44.7%) had RSTD in anterior leads (V1-V3). The mean EF of patients was 44.662 and 49.678.8 in those with RSTD and those without RSTD respectively. This difference was statistically significant; p= 0.043. Among 55 patients with RSTD 32 (58.2%) had an EF 40% and 23 (41.8%) had EF 40%. Among 25 patients without RSTD 22 (88%) had an EF 40% and 3 (12%) had EF 40%. This difference was statistically significant; p= 0.008. However, the mean EF was not significantly different in those with apicolateral RSTD and those with anterior RSTD respectively; p= 0.723. Conclusion: About two third of the patients with acute inferior wall MI had reciprocal ST segment changes in apicolateral and anterior leads. The LVEF was significantly lower among those patients with reciprocal changes. Conversely, the proportion of patients with LVEF 40% was significantly higher among those with reciprocal changes. However, there was difference in EF between apicolateral and anterior lead reciprocal changes.