DOBUTAMINE ECHOCARDIOGRAPHY AND MYOCARDIAL CONTRAST ECHOCARDIOGRAPHY - 2 NEW TECHNIQUES FOR THE ASSESSMENT OF MYOCARDIAL VIABILITY

As investigators have discovered that cardiac regions displaying resti ng wall motion abnormalities are not the necessary equivalent of myoca rdial scar (and therefore of irreversible injury) but are potentially viable regions rendered dysfunctional by stunning or hibernation, a ne w field of medicine has developed to identify viable myocardium that c an improve in function after revascularization. Moreover, improvements in myocardial preservation and perfusion during coronary artery bypas s grafting and percutaneous transluminal coronary angioplasty have ena bled patients with poor resting ejection fractions to undergo safer re vascularization. In this review, we describe briefly the diagnostic te chniques most commonly used in identifying dysfunctional but viable my ocardium. We give specific attention to the assets and limitations of these techniques and special emphasis to 2 promising new techniques: d obutamine echocardiography and myocardial contrast echocardiography.