no-reflow phenomenon
Impaired myocardial perfusion despite successful restoration of epicardial coronary flow, typically occurring after reperfusion therapy.
Full Definition
The no-reflow phenomenon refers to the inability to achieve adequate myocardial tissue perfusion despite successful restoration of normal epicardial coronary artery flow. This complication most commonly occurs following primary percutaneous coronary intervention for acute myocardial infarction, affecting approximately 5-25% of patients. The phenomenon is caused by microvascular obstruction due to distal embolization of thrombotic debris, endothelial swelling, or capillary compression from tissue edema. No-reflow is associated with larger infarct size, reduced left ventricular function, and increased mortality. It can be assessed angiographically using TIMI flow grades and myocardial blush grades, or with advanced imaging techniques.
Usage
Usage note: Should be distinguished from epicardial flow problems; often requires specification of treatment approach.
In Context
- "Despite TIMI 3 flow in the epicardial vessel, no-reflow phenomenon was evident by poor myocardial blush grade." — Primary PCI report
- "Adenosine and nitroprusside were administered to treat the no-reflow phenomenon following stent deployment." — Interventional procedure note