perfusion reserve
The ratio of maximal stress myocardial blood flow to resting blood flow, indicating coronary vasodilatory capacity.
Full Definition
Perfusion reserve, also known as coronary flow reserve, is a quantitative measure of the heart's ability to increase blood flow in response to increased metabolic demand or pharmacological stress. It is calculated as the ratio of peak stress myocardial blood flow to baseline resting flow. Normal perfusion reserve values are typically greater than 2.0, with values below 2.0 suggesting impaired coronary microvascular function or epicardial coronary stenosis. This parameter is particularly valuable for detecting balanced ischemia and microvascular disease that may not be apparent on qualitative perfusion imaging.
Usage
Usage note: Values are typically expressed as ratios without units.
In Context
- "Perfusion reserve was globally reduced at 1.4, suggesting microvascular dysfunction." — Cardiac PET report
- "Regional perfusion reserve was preserved in all territories except the LAD distribution." — Quantitative perfusion analysis