myocardial viability
The presence of living, potentially functional myocardial tissue that may improve with revascularization.
Full Definition
Myocardial viability refers to the presence of viable myocardium in regions with impaired contractile function that have the potential to recover following successful revascularization. Assessment of viability is crucial in patients with ischemic cardiomyopathy to determine whether revascularization will improve cardiac function and clinical outcomes. Various imaging modalities can assess viability, including dobutamine stress echocardiography, nuclear imaging (SPECT or PET), and cardiac MRI with late gadolinium enhancement. Viable myocardium typically shows preserved metabolic activity, contractile reserve, or minimal scar burden. Accurate viability assessment guides treatment decisions between medical therapy, revascularization, or cardiac transplantation.
Usage
Usage note: Distinguish from myocardial stunning (temporary dysfunction) and hibernation (chronic dysfunction with viability).
In Context
- "PET imaging demonstrated myocardial viability in the LAD territory despite wall motion abnormalities." — Viability study report
- "Absence of myocardial viability suggests minimal benefit from revascularization." — Pre-surgical evaluation