Regulation of the coronary vasomotor tone: What we know and where we need to go

The control of coronary blood flow has been studied for decades, but despite our extensive efforts, the critical regulators of flow are largely unknown. One purpose of this review is to summarize some recent concepts about the control of coronary flow and also point out areas where additional knowledge must be acquired. A second purpose of this review is to highlight the need for additional noninvasive measurements of flow that undoubtedly will require further evolution of contemporary technologies, and also application of specific methods toward noninvasive measurements of coronary blood flow. Only after the development of such measurements will the scientific community begin to understand the intricacies of the regulation of coronary flow in human beings.