myocardial stunning
Temporary contractile dysfunction that persists after restoration of blood flow following ischemia, despite absence of irreversible damage.
Full Definition
Myocardial stunning represents a form of reversible ischemic injury where contractile function remains impaired for hours to days after reperfusion, despite restoration of coronary flow and absence of necrosis. The mechanism involves calcium overload and generation of reactive oxygen species during reperfusion. Histologically, myocytes appear viable but may show subtle ultrastructural changes. This phenomenon is important in differentiating viable from non-viable myocardium in clinical and pathological assessments.
Usage
Usage note: Distinguish from hibernating myocardium, which involves chronic adaptation to reduced flow.
In Context
- "The biopsy showed viable myocytes consistent with myocardial stunning rather than irreversible ischemic damage." — endomyocardial biopsy report
- "Evidence of myocardial stunning was present with preserved myocyte architecture despite functional impairment." — research study report