myocardial viability
The presence of living, potentially recoverable myocardial tissue in regions with impaired contractile function.
Full Definition
Myocardial viability refers to the presence of metabolically active, living myocardium in areas with reduced or absent contractile function that may improve with revascularization. Viable myocardium retains cellular integrity and metabolic function despite being dysfunctional due to chronic hypoperfusion (hibernating myocardium) or recent ischemic injury (stunned myocardium). Assessment techniques include dobutamine stress echocardiography, PET metabolism imaging, cardiac MRI with late gadolinium enhancement, and nuclear perfusion imaging. Identifying viable myocardium is crucial for treatment decisions in patients with ischemic cardiomyopathy, as revascularization of viable tissue can improve left ventricular function, symptoms, and prognosis. Non-viable tissue appears as transmural scar and is unlikely to benefit from revascularization.
Usage
Usage note: Specify the imaging technique used for assessment; distinguish between hibernating and stunned myocardium when applicable.
In Context
- "PET imaging demonstrated preserved myocardial viability in the anterolateral wall despite severe dysfunction." — Nuclear cardiology report
- "Late gadolinium enhancement showed extensive transmural scar with minimal viable myocardium." — Cardiac MRI report