Association of Cardiac Axis, Q Waves, Low Voltage QRS-R Waves, R/S Ratio, ST-T Segment Abnormalities with Infarct Electrocardiogram

Abstract

Received: 13 May 2016 Accepted: 22 Jun 2016 Introduction: Electrocardiogram is a useful tool to predict the likely anatomic location of myocardial infarctions (MI). The present study was carried out to assess correlation of cardiac axis, Q waves, QRS-R voltage, R:S, ST-T abnormalities with pertinent infarction site in electrocardiogram. Methods: If Q wave or QS complex are present in any lead, or lead VI-V2 show R:S≥1 or lead VI-V2 have a positive T, the electrocardiogram is called infarct electrocardiogram. Results: ST-T abnormalities and Q waves are important predictors of acute and prior MI with pertinent infarction sites in electrocardiogram. Strong association between pathological Q, loss of R voltage and low QRS voltage is present in prior anterior MI. Acute inferior ischemia is manifested by strong association between ST segment elevation (STE), ST segment depression (STD), T inversion (TI), R/S>1 and hyperacute T while in inferior infarction Q is correlated with low QRS voltage. Acute lateral and anterolateral ischemia is manifested by strong association between STE, STD, TI whereas the infarction is characterized by Q, low QRS in both along with loss of R voltage in the former. Conclusion: ST elevation is the most important abnormality helpful in predicting acute myocardial ischemia along with the presence of hyperacute T waves. The R ≥0.04 s, R/S ratio in leads V1-V2 with or without positive T waves was of less use in prediction of prior MI. Deviation of cardiac axis was not at all related to any of the electrocardiographic lead abnormality in MI.