microvascular obstruction
Impaired perfusion at capillary level despite successful epicardial coronary artery reopening.
Full Definition
Microvascular obstruction (MVO) refers to the impairment of perfusion at the capillary and arteriolar level despite successful restoration of flow in the epicardial coronary artery. This phenomenon occurs due to a combination of distal embolization, vasospasm, tissue edema, and inflammation that affects the coronary microvasculature. MVO is associated with larger infarct size, adverse left ventricular remodeling, and worse clinical outcomes. It can be detected using cardiac magnetic resonance imaging as areas of hypoenhancement or no-reflow on angiography, and represents irreversible myocardial damage.
Usage
Usage note: Can be assessed by multiple modalities including angiography, echocardiography, and MRI.
In Context
- "Cardiac MRI demonstrated extensive microvascular obstruction in the anterior wall territory." — Cardiac magnetic resonance report
- "Despite TIMI 3 flow, microvascular obstruction was evident by poor myocardial blush." — Post-PCI assessment note