When your heart is relaxed it may get enough blood even in the presence of obstructed coronary arteries. However, during physical activity the heart rate and contractility (or strength of contraction) increases, requiring more blood and oxygen than these narrowed arteries are able to supply.
A reduction in blood flow to part of the heart may produce characteristic abnormalities on the electrocardiogram. However these abnormalities are not often seen on an ECG taken at rest, but can be made to appear during exercise.
During exercise stress testing, the exercise is performed by walking on a treadmill or pedaling a stationary bicycle. The treadmills speed and incline, or the bicycles resistance to pedaling, are then progressively increased over time.
To evaluate whether complaints of chest pain is due to coronary artery disease (CAD),
To determine an individuals ability to tolerate exercise or start an exercise program,
To identify abnormal heart rhythms that can be triggered by exercise,
To detect coronary artery disease in a person without symptoms, but has risk factors for CAD, such as smoking, high cholesterol, high blood pressure, diabetes or a family history,
To determine whether blockage of an artery has recurred or coronary artery disease has progressed, especially in patients who previously undergone angioplasty or coronary artery bypass surgery,
To evaluate the effectiveness of medical therapy for arrhythmias, angina or known CAD,
To determine whether an obstruction of moderate severity that was demonstrated on coronary angiography can cause ischemia.
Abraham Salacata, MD, FACC