Recovery of contractility of viable myocardium during inotropic stimulation is not dependent on an increase of myocardial blood flow in the absence of collateral filling
Francesco Barillà, MD*,
Giuseppe De Vincentis, MD ,
Enrico Mangieri, MD*,
Massimo Ciavolella, MD, PhD* ,
Gaetano Pannitteri, MD*,
Francesco Scopinaro, MD,
Giuseppe Critelli, MD* and
Pietro Paolo Campa, MD*
* 2nd Section of Cardiology, Institute of Cardiac Surgery, University "La Sapienza," Rome, Italy
Section of Nuclear Medicine, University "La Sapienza," Rome, Italy
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Figure 1 Bar histograms comparing echocardiographic (top) and scintigraphic results (bottom) at baseline, during low dose dobutamine infusion and postoperatively (POST-REV), in patients with (group A) and without (group B) collaterals. The lack of significant changes in myocardial 99mTc-Sestamibi uptake after dobutamine infusion in patients without collaterals is clearly visible, in spite of a recovery of both function and perfusion detected after revascularization.
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Figure 2 Example of echocardiographic and scintigraphic images obtained in a patient with collaterals (group A) at baseline, during low dose dobutamine infusion and after revascularization (POST-REV). In the top row, a left ventricular end-systolic frame obtained at echocardiographic study in the four-chamber view is shown. In the bottom row, a set of tomographic slices reconstructed along the short axis from left ventricular apex to base (a d) is shown. The decrease in left ventricular end-systolic dimensions at both dobutamine and postrevascularization echocardiographic studies in comparison with the basal study is visible. The functional changes were associated with an increase in 99mTc-Sestamibi uptake detected at dobutamine scan in the areas of the previous infarction in comparison with basal scan, and confirmed after revascularization.
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Figure 3 Example of echocardiographic and scintigraphic images obtained in a patient without collaterals (group B) at baseline, during low dose dobutamine infusion and after revascularization (POST-REV) (image composed as in Fig. 2). The decrease in left ventricular end-systolic dimensions at both dobutamine and postrevascularization echocardiographic studies in comparison with the basal study is visible. Differently from the patient shown in Figure 2 (a patient with collaterals), no change in 99mTc-Sestamibi uptake in the infarcted area is visible at dobutamine scan in comparison with basal scan. A significant increase in tracer uptake was nevertheless detected after revascularization.
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