Hemodynamic, angiographic and scintigraphic correlates of positive exercise electrocardiograms: Emphasis on strongly positive exercise electrocardiograms

Abstract

The results of treadmill exercise electrocardiograms were analyzed in 179 patients with coronary artery disease (greater than or equal to 50% diameter narrowing of one or more vessels). Exercise thallium-201 images were available in 141 of these patients. The exercise electrocardiograms were strongly positive in 51 patients, mildly positive (1 to 1.9 mm ST depression) in 28 patients, falsely negative in 23 patients and uninterpretable in 77 patients. The degree of exercise-induced ST depression did not correlate with left ventricular function, extent of coronary artery disease, exercise heart rates and rate-pressure product and extent of exercise-induced thallium-201 perfusion abnormality. However, the presence of a strongly positive exercise electrocardiogram only at heart rates of 140 beats/min or more or stage III or higher of the Bruce protocol was predictive of less extensive coronary disease and perfusion abnormalities. Thus, the magnitude of ST depression as such during exercise is not predictive of the extent of coronary disease, even in patients with 3 mm or greater ST depression. However, a strongly positive exercise electrocardiogram in the first two stages of the Bruce protocol or at a heart rate of less than 140 beats/min was related to the extent of coronary artery disease and impaired myocardial perfusion, and identified patients with more extensive coronary artery disease and jeopardized myocardium. Therefore, caution should be used in interpreting prognostic data on the basis of the degree of exercise-induced ST depression alone.

Significance of exercise‐induced ST changes in leads AVR, V5, and V1. Discrimination of patients with single‐ or multivessel coronary artery disease

“…An exercise test result was considered positive if there was (1) a horizontal or downsloping ST-segment depression of at least 1 mm, 60 ms after the J point, or (2) an upsloping ST-segment depression of ≥ 1.5 mm, 80 ms after the J point, or (3) an ST-segment elevation of at least 1 mm. 10 All medications were discontinued for at least five half-lives before exercise testing performance. The interpretation was carried out by two independent investigators.…”

Coronary arterial involvement in aortitis syndrome: Assessment by exercise thallium scintigraphy

“…Furthermore, SPECT may have an advantage for the detection of myocardial ischemia compared to planar techniques. In stress ECG, the degree of ST-segment depression did not correlate weil with the extent of coronary artery involvement or left ventricular dysfunction [13]. However, patients with cardiac symptoms can be stratified into different risk groups based on the presence and extent of the exercise-induced 2°iT1 abnormality.…”

Predictors of an ischemic electrocardiographic response in patients with exercise-induced myocardial ischemia

“…1,12,13 While the higher diagnostic sensitivity of perfusion imaging compared to ECG for the detection of myocardial ischemia is well-established, the determinants of diagnostic ECG changes of myocardial ischemia remain poorly defined. For example, even patients with large areas of stress-induced myocardial ischemia do not always demonstrate stress-induced ECG changes.…”