Evaluation of ST-segment changes during and after maximal exercise tests in one-, two- and three-vessel coronary artery disease

Objective-To relate ECG and heart rate (HR) variables during and after exercise testing with the presence of one- ,two- or three-vessel disease defined by angiography. Design-Seventy-three male patients with stable angina pectoris and angiographically verified coronary artery disease underwent a maximal exercise test. From 12-lead ECG recordings and computer averaging ST-amplitude and HR data were measured in consecutive 10-s intervals. Results-In univariate analysis, patients with three-vessel disease had lower maximal exercise capacity, a shorter time to >1 mm ST-depression, more often a clockwise ST/HR recovery loop, more frequently a post-exercise downward ST-segment slope, and a greater ST-deficit at 3.5 min after exercise than patients with one- vessel disease. In multivariate analysis, time to >1 mm ST-depression discriminated between patients with three- and one- vessel disease. In patients with an intermediate time to >1 mm ST-depression a clockwise ST/HR recovery loop and/or a downsloping ST-segment in the post-exercise period were significantly more prevalent in severe vessel disease. Conclusion-Patients with three-vessel disease had a significantly shorter time to >1 mm ST-depression during exercise and more often an abnormal post-exercise ST/HR reaction than those with one-vessel disease.