myocardial stunning
Temporary mechanical dysfunction of viable myocardium following restoration of blood flow after a period of ischemia.
Full Definition
Myocardial stunning refers to prolonged mechanical dysfunction of viable myocardium that persists after restoration of normal coronary blood flow following a period of ischemia. Unlike myocardial necrosis, stunning represents a reversible condition where the affected myocardium gradually recovers function over hours to weeks. This phenomenon is commonly observed after successful reperfusion therapy for acute myocardial infarction, cardiac surgery, or following episodes of severe ischemia. The mechanism involves calcium overload and oxidative stress that temporarily impair contractile function despite adequate oxygen supply. Recognition of stunning is important as it represents viable tissue with potential for functional recovery.
Usage
Usage note: Distinguish from hibernating myocardium, which occurs with chronic ischemia.
In Context
- "Post-reperfusion echocardiography showed evidence of myocardial stunning in the anterior wall." — post-procedure report
- "The wall motion abnormality was attributed to myocardial stunning rather than permanent damage." — cardiology consultation