Figure 7
From: Anti-ischemic therapy and stress testing: pathophysiologic, diagnostic and prognostic implications
Schematic illustration of the principle underlying the impact of antianginal therapy on different markers of ischemia: regional function and perfusion imaging. At rest, perfusion is homogeneously distributed between endocardial and epicardial layers. In the presence of a significant coronary stenosis, vasodilation induced by pharmacologic stress, provokes a subendocardial underperfusion with a relative epicardial overperfusion which is translated into an impairment of function (echocardiographic dyssynergy) and perfusion (reversible defect at scintigraphy). Medical therapy at time of testing re-equilibrates the imbalance between subendocardial and subepicardial layers, but it affects only function.