Robert J. Ascuitto

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ABSTRACT: Isolated, paced, isovolumetrically beating piglet hearts (n = 37) underwent retrograde aortic perfusion with a crystalloid solution during three periods: 1) baseline (coronary perfusion pressure 60 mm Hg), 2) ischemia (coronary flow 10% of baseline for ± 80 min), and 3) reperfusion (perfusion pressure returned to baseline). In one group of hearts,(More)
Flow energy dissipation reduces cardiac efficiency, particularly in the Fontan-modified, single-ventricle heart. To provide insight into flow energetics relevant to Fontan-type anatomy, a simple, analytical description of fluid motion was employed. Mechanical energy balance and the force-momentum relationship were used to describe theoretical pressure(More)
Pressure loss from flow energy dissipation may impair cardiac performance when a heart with a single ventricle must support the circulation. Therefore, the goal of this study was to use a simple description of fluid motion to provide insight into flow energetics relevant to Fontan-type procedures. Our findings indicate that when either the cross-sectional(More)
The developing heart undergoes a remarkable metabolic transformation as it adjusts to the higher-oxygen, extrauterine environment. During gestation, glycolysis and lactate oxidation constitute the major sources of adenosine triphosphate (ATP) for the fetal heart. After birth, however, there is a rapid shift from carbohydrate to fatty acid utilization.(More)
ABSTRACT: Cardiac effects of the neuropeptide pituitary adenylate cyclase activating polypeptide (PACAP) have not previously been reported. We investigated the influence of PACAP, vasoactive intestinal polypeptide (68% homology with PACAP) and the β-adrenergic receptor agonist isoproterenol on contractile function and coronary vascular tone in isolated(More)
The objective of this study was to test whether chronically hypoxic immature hearts exhibit greater tolerance to no-flow ischemia than normoxic hearts. Rabbits (N = 36) were raised from birth to 5 weeks of age in either hypoxic (10% O2/90% N2) or normoxic (room air) environment. Isolated, isovolumically beating hearts, with a fluid-filled balloon catheter(More)
We investigated mechanical and metabolic responses in isolated, isovolumically-beating, pig hearts (n = 7), 12 h to 2 days of age; subjected to hypoxia followed by reoxygenation. Hearts were perfused with an erythrocyte-enriched (hematocrit approximately 15%) solution during 3 consecutive 30-min periods: pre-hypoxia, arterial perfusate [O2] = 7.6 +/- 0.2(More)
BACKGROUND Various pulmonary valve substitutes, with their inherent limitations, have been used in children and young adults. We chose the Medtronic Freestyle (Medtronics, Minneapolis, MN) valve because of its excellent hemodynamics, known durability in adults, and design features that allow modifications during implantation. METHODS Over a 3 1/2 year(More)