Contrast echocardiography for the assessment of myocardial viability

PURPOSE OF REVIEW: The availability of an accurate, non-invasive method for distinguishing viable from irreversibly damaged myocardium, after acute myocardial infarction or in chronic coronary artery disease, is important in clinical decision making. Such a tool would enable physicians to identify patients most likely to benefit from revascularization strategies in patients with coronary artery disease and left ventricular dysfunction. Myocardial contrast echocardiography is a new technique that utilizes acoustically active gas-filled microspheres (microbubbles), which remain exclusively in the intravascular space and allow the simultaneous assessment of global and regional myocardial structure, function, and perfusion. An increasing body of data supports its role in assessing myocardial viability and predicting the recovery of function. RECENT FINDINGS: Myocardial contrast echocardiography accurately differentiates 'stunning' from necrosis, delineates transmural extent of infarction, predicts recovery of regional and global left ventricular systolic function in the recuperative phase, identifies patients at high risk of left ventricular remodelling, and provides incremental viability data when performed in conjunction with low-dose dobutamine echocardiography. SUMMARY: Technological advances have positioned myocardial contrast echocardiography as a safe, practical bedside technique for the evaluation of myocardial viability. It has comparable accuracy with other non-invasive imaging techniques, such as dobutamine stress echocardiography, radionuclide scintigraphy and cardiac magnetic resonance imaging.