assessment of myocardial viability: selection of patients for viability study and revascularization

the aim of this article is to review the application of current imaging techniques used for the detection of viable myocardium. each technique is discussed briefly, and the more commonly used techniques are compared. the imaging techniques reviewed herein are dobutamine stress echocardiography, single photon emission tomography, magnetic resonance imaging, positron emission tomography with f-18 fluorodeoxyglucose, and recently introduced tissue doppler imaging. the estimation of the amount of viable myocardium that could predict a better outcome after revascularization being a challenging issue, the present article also reviews a variety of cut-off points suggested by different investigators as adequate viable myocardium for revascularization and presents a summary of clinical, angiographical, and echocardiographic findings that could assist in selecting patients for viability study.