Excerpt

The left ventricular (LV) dysfunction exhibited by the patient is of equivocal origin. Nuclear imaging provides a very well-validated, versatile series of tests for proper diagnosis of disease pathophysiology, with the added, equally well established benefit of incremental information on patient prognosis and guidance towards optimal therapy (Table 1). In this case, the patient should first undergo a perfusion test, to identify or rule out an ischemic origin of LV dysfunction, and to distinguish between ischemia and myocardial infarction. If a fixed perfusion defect is present, a subsequent viability study using metabolic tracers can assist in selecting the appropriate treatment course. In addition, independent of ischemic or nonischemic origin, complementary assessment of absolute myocardial blood flow can identify severity of global microcirculatory dysfunction as a prognostic marker, and imaging of myocardial sympathetic innervation may be employed to determine individual risk of arrhythmia or heart failure progression. …