myocardial hibernation
A state of chronic contractile dysfunction due to reduced coronary blood flow, representing an adaptive response to preserve myocyte viability.
Full Definition
Myocardial hibernation is a protective mechanism where chronically ischemic but viable myocardium downregulates its contractile function to match reduced oxygen supply. This adaptive response preserves cell viability and energy stores while maintaining basic cellular functions. Histologically, hibernating myocardium shows dedifferentiation with loss of sarcomeres, glycogen accumulation, and small mitochondria, but without necrosis. The condition is potentially reversible with revascularization, distinguishing it from irreversible ischemic injury. Identification of hibernating myocardium is crucial for determining candidates for revascularization procedures.
Usage
Usage note: Distinguish from myocardial stunning, which occurs after reperfusion.
In Context
- "The endomyocardial biopsy showed features consistent with myocardial hibernation including cellular dedifferentiation and glycogen accumulation." — research biopsy report
- "Viability studies demonstrated extensive myocardial hibernation in the anterior wall, suggesting potential benefit from revascularization." — nuclear medicine report