Postexercise Electrocardiogram in Patients With Abnormal Resting Electrocardiograms

One hundred and ten patients with chest pain syndromes and resting electrocardiograms demonstrating ST-T abnormalities and/or prior transmural myocardial infarctions were studied by means of the Master's two-step exercise test and selective coronary cine arteriography. Criteria for negativity were modified so that subjects with postexercise heart rates less than 110 beats/min, who did not develop significant ST-segment changes, were excluded from evaluation. Eighty-six per cent of the coronary artery disease group and 27% of the normal coronary artery group had positive postexercise electrocardiograms. Conversely, of the patients with positive results, 88% had anatomic coronary artery disease. With this degree of stress, positive responses ≧2 mm were invariably associated with multi-vessel disease. The type of pre-existing ECG abnormality did not influence either the frequency or severity of positive responses. False-negative subjects had no distinctive features relating to type of abnormal electrocardiogram, or location of vessel involvement, although most of these patients had significant disease of only one major coronary artery.