BACKGROUND: The purpose of this study was to examine the ability of real-time myocardial contrast echocardiography (MCE) with power modulation to quantitate myocardial blood flow (MBF) and to assess its transmural distribution in open-chest dogs undergoing partial or total coronary stenoses. METHODS AND RESULTS: MBF was measured in 12 dogs instrumented with a cuff occluder around the left anterior descending coronary artery at rest, during partial coronary stenosis (during infusion of adenosine), and during coronary occlusion. The MCE-derived rate of microbubble velocity, beta, and myocardial blood volume, A, were obtained by curve fitting of videointensity versus time plots, after the transient destruction of microbubbles by high-energy ultrasound. The data were compared with MBF measured with radiolabeled microspheres. Significant correlations were found between radiolabeled microsphere-derived MBF and both beta (r = 0.93) and the product of A x beta (r = 0.91). MCE beta reserve also correlated well with microsphere-derived flow reserve. Comparing endocardial/epicardial MCE ratios and microsphere-derived MBF ratios, significant correlation was also found between endomicropsheres/epimicrospheres MBF ratio and both endo/epi beta (r = 0.90) and endo/epi A x beta (r = 0.88). CONCLUSIONS: Real-time power modulation MCE allows for an accurate quantification of MBF and of its transmural distribution in open-chest dogs undergoing partial or total coronary stenoses.
BACKGROUND: The purpose of this study was to examine the ability of real-time myocardial contrast echocardiography (MCE) with power modulation to quantitate myocardial blood flow (MBF) and to assess its transmural distribution in open-chest dogs undergoing partial or total coronary stenoses. METHODS AND RESULTS: MBF was measured in 12 dogs instrumented with a cuff occluder around the left anterior descending coronary artery at rest, during partial coronary stenosis (during infusion of adenosine), and during coronary occlusion. The MCE-derived rate of microbubble velocity, beta, and myocardial blood volume, A, were obtained by curve fitting of videointensity versus time plots, after the transient destruction of microbubbles by high-energy ultrasound. The data were compared with MBF measured with radiolabeled microspheres. Significant correlations were found between radiolabeled microsphere-derived MBF and both beta (r = 0.93) and the product of A x beta (r = 0.91). MCE beta reserve also correlated well with microsphere-derived flow reserve. Comparing endocardial/epicardial MCE ratios and microsphere-derived MBF ratios, significant correlation was also found between endomicropsheres/epimicrospheres MBF ratio and both endo/epi beta (r = 0.90) and endo/epi A x beta (r = 0.88). CONCLUSIONS: Real-time power modulation MCE allows for an accurate quantification of MBF and of its transmural distribution in open-chest dogs undergoing partial or total coronary stenoses.
Authors: Bernard Cosyns; Steven Droogmans; Sophie Hernot; Céline Degaillier; Christian Garbar; Caroline Weytjens; Bram Roosens; Danny Schoors; Tony Lahoutte; Philippe R Franken; Guy Van Camp Journal: Cardiovasc Diabetol Date: 2008-09-02 Impact factor: 9.951