Single photon emission computed tomography (SPECT) myocardial perfusion imaging

SPECT MPI is one of the most popular tests carried out to detect myocardial ischemia, evaluate patients with established ischemic heart disease, or follow up the outcome of bypass surgery or stent placement. It uses a physical or pharmacological stress.

SPECT MPI commonly is performed with exercise stress to induce coronary hyperemia, particularly suitable for patients with exertional symptoms, because this provides the opportunity to link the symptoms induced during exercise to the location, extent, and severity of abnormal perfusion patterns. Moreover, performing exercise stress in conjunction with MPI allows the opportunity to incorporate additional information on functional capacity, stress-induced electrocardiographic changes or arrhythmias, and use of heart rate reserve and heart rate recovery in the assessment of CAD probability or prognosis. In individuals who are incapable of attaining a sufficient level of exercise, SPECT MPI can be yet performed using a pharmacologic stress to induce coronary hyperemia either directly or indirectly. The most widely used agents for pharmacologic stress testing can be divided into those that act as coronary arteriolar vasodilators (adenosine, dipyridamole, and regadenoson) and adrenergic agents such as dobutamine.

For additional information, see the section about Nuclear Cardiac Imaging.