The concept of myocardial viability

Myocardial viability: Certain zones of ischemic, akinetic or severely hypokinetic myocardium are capable of recovering normal contractile function. This is termed myocardial viability and occurs in two different situations: myocardial stunning and myocardial hybernation, Myocardial stunning: This term designates temporary but prolonged impairment of myocardial function resulting from a brief episode of ischemia before reperfusion, Myocardial hibernation: Hibernation designates prolonged but potentially reversible myocardial contractile dysfunction caused by chronic myocardial ischemia and persisting at least until blood flow is restored. Clinical consequences: Theoretically reversible, myocardial stunning or hibernation can have devastating effects ii they persist too long. Revascularization with angioplasty or bypass surgery is indicated. Diagnosis: The degree of myocardial viability in akinetic zones can be determined by assessing preserved inotropic capacity with stress echocardiography and/or evidencing metabolic activity with isotopic techniques (myocardial scintigraphy, positron emission tomography).