Combination of Dobutamine and Myocardial Contrast Echocardiography to Differentiate Postischemic From Infarcted Myocardium

Abstract

Contractile reserve and perfusion data are complementary when assessing regional wall motion abnormalities in postischemic myocardium. DE alone cannot differentiate postischemic from infarcted myocardium; simultaneous data on myocardial perfusion are required. The combination of DE and MCE is superior to either technique alone for identifying the absence of myocardial necrosis.

Quantitative Assessment of Myocardial Viability After Infarction by Dobutamine Magnetic Resonance Tagging

“…Our findings are in agreement with those of Meza et al, 17 who recently demonstrated in a canine model that the presence of contractile reserve in itself does not exclude the presence of regional necrosis. In their study, dogs with MI documented by TTC staining had significant improvement in regional function (percent thickening fraction went from Ϫ7Ϯ22% after reperfusion to 14Ϯ13% with 10 g ⅐ kg Ϫ1 ⅐ min Ϫ1 dobutamine).…”

“…23 With more rapid imaging, more myocardial regions could be sampled, and 2-and 3-dimensional analysis 24,25 of the tagged MR images could be performed, yielding important information with regard to the direction of intramyocardial strains although sacrificing the transmural resolution of the 1-dimensional technique. The combination of quantitative assessment of functional reserve and assessment of myocardial perfusion by either myocardial contrast echocardiography 17,26 or MR contrast imaging may be superior to either technique alone. Our group and others have recently demonstrated the utility of MR contrast infusion to evaluate patients with MI 27,28 and predict return of function on the basis of contrast uptake patterns.…”

Stunning, Hibernation, and Assessment of Myocardial Viability

“…28,[31][32][33][34][35][36] The strengths of echocardiography-based techniques include safety, portability, low cost, and widespread availability of equipment. The main limitation is that the technique is highly operator dependent with high interobserver and intercenter variability.…”

Assessment of Myocardial Postreperfusion Viability by Intravenous Myocardial Contrast Echocardiography

“…[1][2][3][4][5][6][7] From MCE produced by direct coronary injection, patterns of opacification consisting of absent, partial/patchy, 3,6 and normal uptake [1][2][3][4][5][6][7] have been observed in the reperfused zone shortly after recanalization. The absence of myocardial opacification after reperfusion has been associated with necrosis, as evidenced by a failure to recover function at follow-up.…”

“…Of greatest importance, it has been found that myocardial dysfunction may occur even in the presence of contrast enhancement 4 -6 and that an additional assessment of the response to dobutamine stress may be necessary to establish viability. 6,7 Thus, alternative methods by which to identify infarcted but opacified myocardium after reperfusion are needed.…”