Alive but... Hibernating myocardium is heart muscle that is viable and alive but unable to contract normally. It is generally related to inadequate blood supply to that area of the heart.
Ischemic myocardium. The definition of ischemic myocardium is poor heart function in the setting of poor cardiac circulation. When the circulation is repaired, the heart function improves.
See below. It is a chronically low blood supply of the heart due to blockage of the artery resulting in low contractivity of the heart.
Heart muscle that. Gets enough blood flow to survive but does not get enough to function properly.
Time. Stunned myocardium implies a short-term injury to the heart resulting in decreased function of the heart which recovers in 10-14 days. Hibernating myocardium implies a chronically decreased blood supply to the heart which results in poor heart function. Unlike stunned myocardium, the heart function in hibernating myocardium will not improve until the blood supply is repaired.
Excellent question. Stunned usually refers to reduced ejection fraction in the setting of normal perfusion, i.e., takotsubo, stress induced cmp, which usually recover rapidly. Hybernating usually refers to ischemic myocardium with reduced lv function., i.e., patients with CAD who have iw hypokinesis with reduced initial perfusion on stress imaging though with recovery of perfusion noted on delayed viability.
Timing. Stunned myocardium usually refers to a sudden event like a heart attack after which the heart does not function properly. If it is not completely damaged, the stunned heart may recover. Hibernating myocardium is not functioning well because of a chronic lack of blood flow to the heart and may improve if that blood supply is restored.
You don't. you determine viable vs non viable. Stunned vs hibernating is a matter of chronic ischemia (hibernating) and an acute event (stunned)
Stunned/Hibernating. Stunned myocardium has normal perfusion but abnormal wall motion. Hibernating myocardium has abnormal perfusion and abnormal wall motion. Hope this answers your question.