Myocardial viability assessment

Myocardial viability assessment


Myocardial viability assessment: The term viable myocardium is applied to myocardium with a potentially reversible contractile dysfunction in patients with coronary artery disease. It can be divided into stunned myocardium and hibernating myocardium. Stunned myocardium has prolonged contractile dysfunction after a transient ischemic episode and coronary reperfusion. This automatically recovers over a period of time. Stunned myocardium is commonly noted after thrombolysis and primary percutaneous coronary intervention. Hibernating myocardium has reduced contractile function due to persistently impaired coronary blood flow. Hibernating myocardium regains contractile function partially or completely after revascularization.

The goal of myocardial viability assessment is to identify those patients who will improve with coronary revascularization. It is useful to triage those with heart failure into ones which require revascularization vs those who require left ventricular assist devices or cardiac transplantation. It can predict the recovery of myocardial function with treatment and thus the prognosis.

Assessment of myocardial contractile reserve can be done by echocardiography and cardiac magnetic resonance (CMR) imaging. Segmental thickening and systolic function can be assessed by these modalities. Myocardial perfusion can be assessed by single photon emission computerized tomography (SPECT) and myocardial contrast echocardiography. Metabolism of myocardial cells are assessed by positron emission tomography. Myocardial scar (dead myocardium) can be detected by CMR (late gadolinium enhancement or LGE) and multidetector computerized tomography (MDCT).