Exercise-induced ST-segment depression is primarily monitored in which phase of an exercise test?

Exercise-induced ST-segment depression is primarily monitored during the exercise phase of an exercise test. During this phase, the heart is under increased workload as the intensity of the exercise rises. This heightened demand can lead to changes in cardiac function and blood flow, which may manifest as ST-segment depression on an electrocardiogram (ECG). This depression can indicate the presence of myocardial ischemia, which is a reduction in blood flow to the heart muscle, often due to coronary artery disease. Monitoring during the exercise phase allows for the observation of the heart's response to physical stress in real time, providing valuable insights into its health and functional capacity.

The warm-up phase is typically less intense and serves primarily to prepare the body for more vigorous exercise, so significant cardiovascular changes are less likely to be observed there. Similarly, during the recovery and cool down phases, the heart rate and workload decrease, and the likelihood of detecting ST-segment changes related to ischemia diminishes, making those phases less relevant for monitoring exercise-induced ST-segment depression. Hence, it is during the exercise phase that the most critical data regarding ST-segment changes is collected and analyzed.