Role of oesophageal electrocardiograms in differentiation of old anteroseptal myocardial infarction from emphysema in cases with poor R wave progression in precordial leads.

R wave height, S wave depth and the R/S ratio on electrocardiograms obtained with unipolar oesophageal lead recorded at various levels were studied in 54 cases with emphysema without myocardial infarction and 46 cases with healeeed anteroseptal myocardial infarction. All patients had poor R wave progression in anterior precordial leads. The criterion of R wave height of greater than or equal to 7.5 mm at the ventricular level oesophageal electrocardiogram was most sensitive (85.7%), specific (80%) and accurate (82.4%) for the diagnosis of healed anteroseptal myocardial infarction.