flow-mediated dilation
A non-invasive ultrasound test measuring endothelial function by assessing brachial artery dilation in response to increased blood flow.
Full Definition
Flow-mediated dilation (FMD) is a non-invasive ultrasound technique that assesses endothelial function by measuring brachial artery diameter changes in response to reactive hyperemia. The test involves inflating a blood pressure cuff to create temporary ischemia, then measuring arterial dilation following cuff release as increased shear stress stimulates nitric oxide release from the endothelium. Normal FMD responses are typically >7-10%, with impaired responses indicating endothelial dysfunction, an early marker of atherosclerosis. FMD testing is valuable in research settings and specialized clinics for assessing vascular health in patients with diabetes, hypertension, and other cardiovascular risk factors. The technique can evaluate the effects of therapeutic interventions on vascular function and predict future cardiovascular events.
Usage
Usage note: Hyphenate flow-mediated; FMD is standard abbreviation in clinical contexts.
In Context
- "Flow-mediated dilation testing revealed impaired endothelial function with only 4% brachial artery dilation." — Vascular function laboratory report
- "FMD assessment was performed to evaluate vascular effects of the new antidiabetic medication." — Clinical trial protocol