The correlation of the computer quantitated treadmill exercise electrocardiogram with cinearteriographic assessment...

One hundred and twenty-five consecutive patients being submitted for coronary cinearteriography were subjected to preliminary graded exercise testing using a Quinton treadmill and ECG data computer. Patients with disease of the left main coronary artery are at particular risk during coronary arteriography and it was hoped that exercise testing might identify these patients. This hope was not realised. A satisfactory end point to the exercise test was either the attainment of 85% of the maximal heart rate assessed for age, or ST segment depression greater than 2 mm. Exercise induced angina also formed an end point to the test and was considered a positive result. Results were determined by McHenry's discriminant analysis. The sensitivity of the exercise test was 66, 88 and 92% for one, two and three vessel disease respectively. Specificity was at least 83%. Exercise induced ST segment elevation occurred in four patients all of whom had previous extensive anterior wall infarction. Exercise testing is without risk in patients with ischaemic heart disease provided well defined precautions are taken.