Exercise Stress Test has remained the hallmark of assessing coronary heart disease for long. However, the need for a pharmacologic stress agent arises when the patient is not able to attain an acceptable level of exertion by exercise or unable to exercise due to physical limitation or pre-existing medical conditions. In the case of myocardial perfusion scintigraphy, differences in regional cardiac blood flow result in nonhomogeneous uptake of the radiopharmaceutical which is the primary criterion used to diagnose coronary artery disease.
During exercise-induced vasodilation, blood flow in myocardial regions supplied by stenotic coronary arteries does not increase to the extent that it does in areas supplied by normal coronary arteries. Pharmacologic stress agents offer an alternative to exercise in patients who are unable to attain an acceptable level of exertion or who are unable to…
