In cardiology, hibernating myocardium is a state when some segments of the myocardium exhibit abnormalities of contractile function. These abnormalities can be visualised during echocardiography or ventriculography. The finding of a perfusion or metabolic mismatch between PET-FDG and PET-NH3 is indicative of decreased metabolism. The wall of the affected segments is hypo-, a-, or dyskinetic.
The phenomenon is highly significant clinically because it usually manifests itself in the setting of chronic ischemia, that is potentially reversible by revascularisation via cardiac catheterization. The regions of myocardium are still viable and can restore its function. There develops a new steady state between myocardial blood flow (MBF) and myocardial function, MBF reduced and in consequence function is reduced too. The clinical situations where one can expect hibernating myocardium are: