An adenosine stress test is a procedure used in place of an exercise stress test, according to WebMD. This pharmacological stress test uses adenosine to induce stress on the cardiovascular system to evaluate the flow of blood. It is used with patients who cannot exercise, have decreased functioning abilities or cannot elevate their heart rates enough with exercise.
Adenosine is one of the drugs used in pharmacological stress tests. It is a coronary vasodilator and is administered intravenously, explains UPMC. It opens coronary arteries in a manner similar to exercise; however, it causes only a small increase in the heart rate, states Cleveland Clinic. Adenosine increases the blood flow of healthy, normally functioning vessels. Blocked or clogged vessels do not experience the blood flow of normal vessels.
A radioactive isotope is injected into a vein while at rest, which is before the adenosine infusion and after the drug is administered. A magnetic resonance imaging scan takes pictures of the heart as the dye flows through it. The images taken while at rest are termed "resting images," explains UPMC. Images taken after the drug is administered are "stress images." A doctor compares and evaluates these pictures to make a diagnosis.