For a stress echo test, how do you determine if you use dobutamine or adenosine?
Also, your website states you use lexiscan with thallium for the nuclear stress test. When do you know which test to use and which drugs to use?
Submitted by Lindsay from Longmont United Hospital on 07/16/2014
Question 1- Use dobutamine for stress echo. While adenosine has been used in certain research applications, it is not generally accepted for most clinical applications of echocardiography.
Question 2 – Regarding radionuclide (“nuclear”) cardiac imaging, there are 4 approved radiopharmaceuticals for assessing myocardial perfusion with SPECT. One (teboroxime) is rarely used because of logistic difficulties and limited availability. Choosing between the others depends on a number of technical and logistic factors, but all are acceptable in most cases. Agents labeled with technetium-99m (sestamibi and tetrofosmin) instead of thallium-201 may have a clinical advantage in obese patients and are technically less demanding to use.
There are additional radionuclides that can be used with PET (Positron Emission Tomography), but these require a special (PET) imaging device, so their use is more limited, though it is increasing.
With respect to pharmacologic stress testing with radionuclides, 4 agents are widely available: dipyridamole, adenosine, and regadenoson are vasodilators, and dobutamine is an inotropic agent. The vasodilators have differences in type and duration of their side effects but their clinical accuracies are similar. Most laboratories prefer a vasodilator over dobutamine due to the side effect profiles, but accuracy is similar for all 4 agents when used in conjunction with radionuclide imaging. Regadenoson is the easiest to use for technical reasons but has had less documented clinical experience.