Stress echocardiography: basics and noninvasive assessment of myocardial viability.

Myocardial viability within the infarct zone is an important determinant for left ventricular (LV) function recovery after interventional coronary revascularization. Echocardiographic techniques are highly valuable in identifying hibernation, especially in conjunction with dobutamine titration. Low doses may detect the inotropic reserve by significant enhancement of segmental wall motion abnormalities while high doses may surpass the ischemic threshold and wall motion deteriorates (biphasic response). According to the Task Forces on Clinical Application of Echocardiography by the American Heart Association (AHA) in cooperation with the American College of Cardiology (ACC), dobutamine echocardiography (DE) is officially recommended for the purpose of clinical decision making in respect of revascularization therapies (whether during the subacute infarct period or especially in chronic LV dysfunction due to coronary artery disease (CAD)). New methods such as strain rate imaging implemented in DE are on the way to give us quantitative measures of the amount of viability.