coronary flow reserve
The ratio of maximal coronary blood flow during hyperemia to resting coronary blood flow, indicating coronary vasodilatory capacity.
Full Definition
Coronary flow reserve (CFR) is a physiological parameter that represents the ability of the coronary circulation to increase blood flow in response to increased metabolic demands. It is calculated as the ratio of peak hyperemic flow to baseline resting flow, typically measured using pharmacologic vasodilators like adenosine or dipyridamole. Normal CFR values are typically >2.5, with reduced values indicating impaired microvascular function or epicardial stenosis. CFR can be assessed invasively using Doppler flow wires during catheterization or non-invasively using echocardiography, PET, or MRI. This parameter is particularly valuable for evaluating the functional significance of intermediate coronary stenoses and assessing microvascular dysfunction in conditions like diabetes or hypertension.
Usage
Usage note: Always include measurement method and reference normal values when reporting CFR.
In Context
- "The coronary flow reserve was markedly reduced at 1.8, indicating significant microvascular dysfunction." — Invasive physiology report
- "PET imaging demonstrated preserved coronary flow reserve in all vascular territories." — Nuclear cardiology report