Assessing Coronary Blood Flow Physiology in the Cardiac Catheterisation Laboratory.

Background: Contemporary management of coronary disease focuses on the treatment of stenoses in the major epicardial vessels. However, myocardial blood flow is known to be contingent on a range of factors in addition to the patency of the epicardial vessels. These include anatomical and physiological factors such as the extent of myocardium supplied by the vessel, systemic blood pressure, the natural variation in vascular tone in response to physiological needs which allows for coronary autoregulation and pathological factors such as the presence of downstream obstruction to flow due to disease of the small coronary vessels or myocardium.