Cardiac stressing agents

What are Cardiac stressing agents?

A cardiac stressing agent is used to stimulate the heart and increase workload.

They are used in a cardiac stress test which monitors the heart’s ability to cope with stress, starting from rest and then with an increasing workload. Once the cardiac stressing agent is administered the heart is monitored by echocardiogram or isotope imaging for any changes in blood flow through the heart muscle tissue or any structural differences.

Adenosine, dipyridamole (Persantine), and dobutamine are the most widely available pharmacologic agents for stress testing. Regadenoson, an adenosine analog, has a longer half-life than adenosine, and therefore a bolus versus continuous administration. Adenosine, dipyridamole, and regadenosine are cardiac vasodilators.

The stress agent is injected through a peripheral intravenous line, which will increase blood flow through the coronary vasculature and mimic a response similar to exercise stress testing. Once a peak effect is attained, a small amount of radioactive material is inserted through the peripheral intravenous line.

Chemical stress tests are a common practice. In this situation, medications are given that either cause the coronary arteries to dilate or cause the heart rate to increase. The chemical response is similar to the response caused by exercise. Through your IV, a chemical called Lexiscan will be injected.