Background Myocardial blood flow(MBF) can be quantified with myocardial contrast echocardiography (MCE) during a venous infusion of microbubble. A minimal MBF is required to maintain cell membrane integrity and myocar...Background Myocardial blood flow(MBF) can be quantified with myocardial contrast echocardiography (MCE) during a venous infusion of microbubble. A minimal MBF is required to maintain cell membrane integrity and myocardial viability in ischemic condition. Thus, we hypothesized that MCE could be used to assess myocardial viability by the determination of MBF. Methods and ResultsMCE was performed at 4 hours after ligation of proximal left anterior descending coronary artery in 7 dogs with constant venous infusions of microbubbles. The video intensity versus pulsing interval plots derived from each myocardial pixel were fitted to an exponential function: y=A(1-e-βt), where y is Ⅵ at pulsing interval t, A reflects microvascular cross - sectional area (or myocardial blood volume), and βreflects mean myocardial microbubble velocity. The product of A·β represents MBF. MBF was also obtained by ra-diolabeled microsphere method servered as reference. MBF derived by radiolabeled microsphere - method in the regions of normal, ischemia and infarction was 1.5+0.3, 0.7+0.3, 0. 3+0. 2 mL @ min-1@ g-1 respectively. The product of A·β obtained by MCE in those regions was 52. 46±15. 09, 24. 36±3. 89, 3. 74 ±3. 80 respectively. There was good correlation between normalized MBF and the normalized A·β ( r = 0. 81, P=0. 001). Conclusions MCE has an ability to determine myocardial viability in myocardial infarction canine model.展开更多
基金This work was supported in part by grants from thescience and technology foundation of China(39870329).
文摘Background Myocardial blood flow(MBF) can be quantified with myocardial contrast echocardiography (MCE) during a venous infusion of microbubble. A minimal MBF is required to maintain cell membrane integrity and myocardial viability in ischemic condition. Thus, we hypothesized that MCE could be used to assess myocardial viability by the determination of MBF. Methods and ResultsMCE was performed at 4 hours after ligation of proximal left anterior descending coronary artery in 7 dogs with constant venous infusions of microbubbles. The video intensity versus pulsing interval plots derived from each myocardial pixel were fitted to an exponential function: y=A(1-e-βt), where y is Ⅵ at pulsing interval t, A reflects microvascular cross - sectional area (or myocardial blood volume), and βreflects mean myocardial microbubble velocity. The product of A·β represents MBF. MBF was also obtained by ra-diolabeled microsphere method servered as reference. MBF derived by radiolabeled microsphere - method in the regions of normal, ischemia and infarction was 1.5+0.3, 0.7+0.3, 0. 3+0. 2 mL @ min-1@ g-1 respectively. The product of A·β obtained by MCE in those regions was 52. 46±15. 09, 24. 36±3. 89, 3. 74 ±3. 80 respectively. There was good correlation between normalized MBF and the normalized A·β ( r = 0. 81, P=0. 001). Conclusions MCE has an ability to determine myocardial viability in myocardial infarction canine model.
