Stress agents with vasodilatory effect are crucial for myocardial perfusion imaging with the injection of a radiopharmaceutical for diagnosing myocardial ischemia in patients who are unable to attain an acceptable level of exertion or who are unable to exercise due to physical limitations. Dipyridamole is such a coronary vasodilator that facilitates myocardial perfusion imaging. The uptake of radiopharmaceuticals used in myocardial perfusion scintigraphy is proportional to the regional blood flow.
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…
