Publications
Below you can find a list of our published research.
Below you can find a list of our published research.
251 results
Cited 8 times since 1993 (0.3 per year) source: EuropePMC
Pediatric research, Volume 33, Issue 3, 1 1 1993, Pages 295-301 Myocardial perfusion and performance after indomethacin administration in newborn lambs. Klautz RJ, van Bel F, Teitel DF, Steendijk P, Baan J
Indomethacin is a drug widely used to achieve pharmacologic closure of a patent ductus arteriosus in the premature infant. In several vascular beds (brain, kidney, intestine), indomethacin has been shown to cause vasoconstriction. Possible negative effects on myocardial blood flow and performance could be deleterious in premature infants with limited cardiac reserve. Before, during, and 30 and 60 min after administration of 1 mg.kg-1 of indomethacin in nine newborn lambs, we measured coronary bl... Abstract
Cited 13 times since 1993 (0.4 per year) source: EuropePMC
Biology of the neonate, Volume 64, Issue 4, 1 1 1993, Pages 193-200 Cerebral hemodynamics and oxygenation in preterm infants after low-vs. high-dose surfactant replacement therapy. Dorrepaal CA, Benders MJ, Steendijk P, van de Bor M, van Bel F
In thirteen preterm infants receiving surfactant (Curosurf) replacement therapy, changes in cerebral hemodynamics and oxygenation were investigated by near infrared spectroscopy. Surfactant instillation led to an instantaneous increase in cerebral blood volume (CBV) in all infants, which was primarily due to an increase in deoxygenated hemoglobin. Five infants received a low dose (100 mg/kg = 1.25 ml/kg) of surfactant and 8 a high dose (200 mg/kg = 2.50 ml/kg). A significantly larger increase in... Abstract
Cited 13 times since 1992 (0.4 per year) source: EuropePMC
European heart journal, Volume 13 Suppl E, 1 1 1992, Pages 28-34 Single and dual excitation of the conductance-volume catheter analysed in a spheroidal mathematical model of the canine left ventricle. Steendijk P, van der Velde ET, Baan J
The conductance method employs a multi-electrode catheter to generate an electrical field and measure intracavitary segmental conductances. Left ventricular (LV) volumes are calculated using an algorithm which assumes the electrical field to be homogeneous. This assumption may be violated leading to a non-linear relation between conductance-derived and true volumes. In addition, this relation may vary between segments. A new method is introduced which uses a more homogeneous field. Volume estima... Abstract
Cited 30 times since 1992 (1 per year) source: EuropePMC
European heart journal, Volume 13 Suppl E, 1 1 1992, Pages 2-6 Ventricular pressure-volume relations in vivo. Baan J, van der Velde ET, Steendijk P
A number of fundamental mechanical properties of cardiac muscle as well as of the total ventricle are discussed. These include: Starling's law, shortening deactivation, homeometric autoregulation, and so-called hyperactivation associated with a small amount of ejection. Whenever appropriate, muscle properties are related to those of the intact ventricle. The phenomenon of load-dependence of the end-systolic pressure-volume relationship (ESPVR) receives particular attention and is placed wit... Abstract
Cited 6 times since 1992 (0.2 per year) source: EuropePMC
European heart journal, Volume 13 Suppl E, 1 1 1992, Pages 15-21 Left ventricular segmental volume by conductance catheter and Cine-CT. van der Velde ET, van Dijk AD, Steendijk P, Diethelm L, Chagas T, Lipton MJ, Glanz SA, Baan J
The ability of the conductance catheter method to measure left ventricular segmental and total volume was evaluated by comparison with the Cine-CT technique. In the seven dogs studied, 19 conductance catheter and simultaneous Cine-CT runs were obtained. High correlation coefficients were found for total volume and segmental volumes, except in the basal segment. However, in most cases there was a significant variability in slope and intercept between animals. Both methods are promising tools for... Abstract
Cited 8 times since 1992 (0.3 per year) source: EuropePMC
European heart journal, Volume 13 Suppl E, 1 1 1992, Pages 40-46 The end-systolic pressure-volume relationship in young animals using the conductance technique. Teitel DF, Klautz RJ, Cassidy SC, Steendijk P, van der Velde ET, van Bel F, Baan J
Evaluation of ventricular performance by the end-systolic pressure-volume relationship (ESPVR) has been extensively performed in the adult heart using the conductance technique. We undertook this study to validate the conductance technique and to generate ESPVRs in the small heart. To validate the technique, we simultaneously measured left ventricular volume by the conductance catheter and biplane cineangiography in nine piglets during changes in volume and contractility. Raw conductance volumes... Abstract
Cited 11 times since 1992 (0.3 per year) source: EuropePMC
Ultrasound in medicine & biology, Volume 18, Issue 5, 1 1 1992, Pages 441-449 Cerebral blood flow velocity: the influence of myocardial contractility on the velocity waveform of brain supplying arteries. Van Bel F, Steendijk P, Teitel DF, de Winter JP, Van der Velde ET, Baan J
Indices of Doppler-derived velocity waveforms of arteries perfusing the brain are used as relative measures of neonatal brain blood flow. Using a dog model, we investigated the influence of changes in myocardial contractility, induced by dobutamine, on the blood flow velocity waveform of the vertebral artery. The following indices of the velocity waveform were investigated during control states and during 5 or 10 micrograms/kg/min dobutamine infusion: peak systolic flow velocity (PSFV), temporal... Abstract
Cited 9 times since 1991 (0.3 per year) source: EuropePMC
Pediatric research, Volume 30, Issue 4, 1 1 1991, Pages 375-380 Acceleration of blood flow velocity in the carotid artery and myocardial contractility in the newborn lamb. van Bel F, Schipper IB, Klautz RJ, Teitel DF, Steendijk P, Baan J
We investigated the influence of quantitative changes in myocardial contractile state, reflected by changes in the end-systolic pressure-volume relationship (its slope and volume intercept) and by changes in the slope of the relationship between change in pressure per unit time and end-diastolic volume induced by beta-adrenergic stimulation or inhibition, on the Doppler derived blood flow velocity wave form of the carotid artery, using a newborn lamb model. Acceleration time of the velocity wave... Abstract
Cited 23 times since 1991 (0.7 per year) source: EuropePMC
Pediatric research, Volume 29, Issue 5, 1 1 1991, Pages 473-482 The end-systolic pressure-volume relationship in the newborn lamb: effects of loading and inotropic interventions. Teitel DF, Klautz R, Steendijk P, van der Velde ET, van Bel F, Baan J
Indices of global systolic performance of the newborn left ventricle exceed those of the adult, despite isolated tissue studies showing immature contractile mechanisms. To evaluate contractility in situ, we investigated the end-systolic pressure-volume relationship (ESPVR) by the conductance technique in nine newborn lambs. After percutaneous placement of catheters, we generated ESPVR by inferior vena cava occlusion, aortic occlusion, and volume infusion in two control states, during three level... Abstract
Cited 74 times since 1991 (2.2 per year) source: EuropePMC
Circulation, Volume 83, Issue 1, 1 1 1991, Pages 315-327 Nonlinearity and load sensitivity of end-systolic pressure-volume relation of canine left ventricle in vivo. van der Velde ET, Burkhoff D, Steendijk P, Karsdon J, Sagawa K, Baan J
The effects of mechanical changes in loading conditions on the left ventricular end-systolic pressure-volume relation (ESPVR) were studied in nine open-chest dogs, including three dogs studied before and after beta-adrenergic blockade. Left ventricular pressure was measured with a micromanometer, and left ventricular volume was measured with a conductance catheter. ESPVRs were obtained by increasing left atrial inflow over wide volume ranges (as much as threefold) under three different condition... Abstract
Cited 19 times since 1986 (0.5 per year) source: EuropePMC
Journal of biomechanics, Volume 19, Issue 10, 1 1 1986, Pages 799-805 Fluid shear as a possible mechanism for platelet diffusivity in flowing blood. Aarts PA, Steendijk P, Sixma JJ, Heethaar RM
Platelet transport theory is based on convection diffusion and describes adequately the influence of wall shear rate, platelet concentration and axial (down stream) position. Until now, the influence of the predominant factors affecting platelet adherence, the hematocrit and the red cell size, was not included in this theory. Their role remained hidden in the platelet diffusivity (Dw), which was assumed to be related to the shear rate (gamma) expressed in s-1 by a power law function Dw = m gamma... Abstract