myocardial perfusion reserve
The ratio of maximal hyperemic myocardial blood flow to resting myocardial blood flow, indicating coronary vascular reserve capacity.
Full Definition
Myocardial perfusion reserve (MPR) is a quantitative measure of coronary microvascular function representing the fold-increase in myocardial blood flow from rest to maximal pharmacologic vasodilation. Normal MPR values typically exceed 2.5, with reduced values indicating impaired coronary flow reserve due to epicardial stenosis, microvascular dysfunction, or both. MPR can be assessed using various imaging modalities including PET, cardiac MRI, and echocardiography with pharmacologic stress. This parameter provides valuable diagnostic and prognostic information, particularly in patients with chest pain and non-obstructive coronary artery disease where microvascular dysfunction may be the underlying etiology.
Usage
Usage note: Normal values typically >2.5; lower values indicate impaired coronary reserve.
In Context
- "Quantitative perfusion analysis revealed reduced myocardial perfusion reserve of 1.8, indicating significant microvascular dysfunction." — Cardiac PET report
- "MPR was preserved in the non-infarct territory despite epicardial disease, suggesting adequate collateral flow." — Perfusion imaging report