Heterogeneity of myocardial perfusion provides the physiological basis of perfusable tissue index.

Abstract

Oxygen-15-water can diffuse into both acutely and chronically ischemic myocardium irrespective of its functional status. The results suggest that PTI is most likely an index of the heterogeneity of myocardial flow rather than an index of the amount of tissue being perfused. Its utility for delineating myocardial viability is thus related to the amount of tissue perfused that has low absolute levels of perfusion or high degrees of flow heterogeneity.