Publications
Below you can find a list of our published research.
Below you can find a list of our published research.
251 results
Cited 25 times since 2002 (1.1 per year) source: EuropePMC
Radiology, Volume 222, Issue 1, 1 1 2002, Pages 127-135 MR flow mapping in coronary artery bypass grafts: a validation study with Doppler flow measurements. Langerak SE, Kunz P, Vliegen HW, Jukema JW, Zwinderman AH, Steendijk P, Lamb HJ, van der Wall EE, de Roos A
Purpose: To validate fast magnetic resonance (MR) flow mapping with intravascular Doppler flow measurements in vitro and in patients with nonstenotic and stenotic coronary artery bypass grafts. Materials and methods: MR and Doppler flow measurements were performed in a small-diameter flow phantom with physiologic flow conditions and at baseline and during adenosine stress in 27 grafts in 23 patients, who were scheduled for cardiac catheterization. At invasive analysis, the grafts were divided in... Abstract
Cited 48 times since 2001 (2.1 per year) source: EuropePMC
American journal of physiology. Heart and circulatory physiology, Volume 281, Issue 6, 1 1 2001, Pages H2697-704 Biventricular systolic function in young lambs subject to chronic systemic right ventricular pressure overload. Leeuwenburgh BP, Helbing WA, Steendijk P, Schoof PH, Baan J
In various clinical situations of congenital heart disease, the right ventricle (RV) is subject to a chronic systemic pressure overload which affects biventricular function and may progress to the development of RV failure. Young lambs (2-3 wk old) underwent adjustable pulmonary artery banding (PAB) at systemic (aortic) level for 8 wk. Biventricular function was determined by using load-independent indexes of global ventricular contractile performance by the end-systolic pressure-volume relation... Abstract
Cited 10 times since 2001 (0.4 per year) source: EuropePMC
The Journal of thoracic and cardiovascular surgery, Volume 122, Issue 4, 1 1 2001, Pages 767-774 Influence of clenbuterol treatment during six weeks of chronic right ventricular pressure overload as studied with pressure-volume analysis. Hon JK, Steendijk P, Petrou M, Wong K, Yacoub MH
Objectives: Chronic pressure overload cardiac hypertrophy produces ventricular dysfunction. There is evidence that clenbuterol, a beta(2)-adrenoceptor agonist, produces cardiac hypertrophy with preserved function in rodents. We sought to determine the cardiac hypertrophic effects of clenbuterol on the thin-walled ventricles of large animals undergoing chronic pressure overload by means of pulmonary artery banding. Methods: Right ventricular pressure-volume loops were obtained in open-chest sheep... Abstract
Cited 82 times since 2001 (3.6 per year) source: EuropePMC
American journal of physiology. Heart and circulatory physiology, Volume 281, Issue 2, 1 1 2001, Pages H755-63 Hypertonic saline method accurately determines parallel conductance for dual-field conductance catheter. Steendijk P, Staal E, Jukema JW, Baan J
Conversion of conductance catheter data to absolute ventricular volumes requires assessment of parallel conductance (G(P)). We determined the accuracy of GP obtained by the hypertonic saline method (G(P)saline) compared with angiographically derived GP (G(P)Angio) and quantified the variabilities of GP for the dual-field conductance catheter method in nine anesthetized sheep studied at baseline, treated with dobutamine, and subjected to volume loading and beta-blockade. G(P)saline and G(P)Angio... Abstract
Journal of the American College of Cardiology, Volume 38, Issue 1, 1 1 2001, Pages 286 Batista's operation: what have we learned? Schreuder JJ, Steendijk P, Baan J, Alfieri O
Cited 29 times since 2001 (1.3 per year) source: EuropePMC
Acta physiologica Scandinavica, Volume 172, Issue 2, 1 1 2001, Pages 97-106 Acute effects of pulmonary artery banding in sheep on right ventricle pressure-volume relations: relevance to the arterial switch operation. Hon JK, Steendijk P, Khan H, Wong K, Yacoub M
The first stage of the two-stage arterial switch operation (ASO) for transposition of the great arteries (TGA) is associated with depressed ventricular function and an unstable immediate post-operative course. It is unclear if this is because of the acute increase in afterload of the thin-walled, low-pressure ventricle by pulmonary artery banding (PAB). To determine the acute effects of afterload increase on the contractile function of thin-walled ventricles, we studied the right ventricular pre... Abstract
Cited 13 times since 2001 (0.6 per year) source: EuropePMC
Early human development, Volume 63, Issue 1, 1 1 2001, Pages 9-21 Endothelin-1 plasma concentration increases in the early phase of pulmonary hypertension development during respiratory distress syndrome: a study in newborn lambs. de Vroomen M, Lopes Cardozo RH, Steendijk P, Frölich M, Baan J, van Bel F
Objective: Elevated plasma concentrations of endothelin-1 (ET-1) have been reported with pulmonary hypertension during respiratory distress syndrome (RDS). However, the exact role of ET-1 in the development of pulmonary hypertension during RDS is unclear. The relative time-course of changes in ET-1 concentrations and pulmonary artery pressure (P(ap)) during RDS may give insight in the role of ET-1. Methods: ET-1 and P(ap) changes were studied in an experimental model of RDS, induced by lung lava... Abstract
Cited 5 times since 2001 (0.2 per year) source: EuropePMC
Early human development, Volume 60, Issue 3, 1 1 2001, Pages 159-170 Inhibition of nitric oxide synthesis following severe hypoxia-ischemia restores autoregulation of cerebral blood flow in newborn lambs. Dorrepaal CA, Steendijk P, Baan J, van Bel F
Birth asphyxia impairs the autoregulatory ability of the cerebral blood flow. Inappropriate synthesis of vasodilatory nitric oxide may be important in this respect. We investigated if nitric oxide synthesis inhibition by N(omega)-nitro-L-arginine (NLA) could restore cerebral autoregulation after severe hypoxia-ischemia (HI). HI was induced in 15 newborn lambs. Cerebral blood flow (carotid artery blood flow [ml/min]: Qcar) and mean aortic blood pressure [mmHg]: MABP) were measured over a 30 min p... Abstract
Cited 17 times since 2001 (0.7 per year) source: EuropePMC
Journal of biomechanics, Volume 34, Issue 1, 1 1 2001, Pages 41-50 Predicting systolic and diastolic aortic blood pressure and stroke volume in the intact sheep. Segers P, Steendijk P, Stergiopulos N, Westerhof N
We developed a mathematical model describing the interaction between the heart and the arterial system. The model was constructed and tested on basis of invasive hemodynamic data in six sheep. Data from a first group of three animals (49 cardiac cycles) were used to assess a template time-varying elastance curve for the left ventricle, while the baseline steady-state data of a second group of three animals were used to assess reference cardiac and arterial parameters in sheep. The model is fully... Abstract
Cited 15 times since 2001 (0.6 per year) source: EuropePMC
American journal of physiology. Heart and circulatory physiology, Volume 280, Issue 1, 1 1 2001, Pages H392-400 Enhanced systolic function of the right ventricle during respiratory distress syndrome in newborn lambs. De Vroomen M, Steendijk P, Lopes Cardozo RH, Brouwers HH, Van Bel F, Baan J
Respiratory distress syndrome (RDS) causes pulmonary hypertension. It is often suggested that this increased afterload for the right ventricle (RV) might lead to cardiac dysfunction. To examine this, we studied biventricular function in an experimental model. RDS was induced by lung lavages in seven newborn lambs. Five additional lambs served as controls. Cardiac function was quantified by indexes derived from end-systolic pressure-volume relations obtained by pressure-conductance catheters. Aft... Abstract
Cited 37 times since 2000 (1.6 per year) source: EuropePMC
Journal of the American College of Cardiology, Volume 36, Issue 7, 1 1 2000, Pages 2104-2114 Acute and short-term effects of partial left ventriculectomy in dilated cardiomyopathy: assessment by pressure-volume loops. Schreuder JJ, Steendijk P, van der Veen FH, Alfieri O, van der Nagel T, Lorusso R, van Dantzig JM, Prenger KB, Baan J, Wellens HJ, Batista RJ
Objectives: The aim of this study was to evaluate the short-term effects of partial left ventriculectomy (PLV) on left ventricular (LV) pressure-volume (P-V) loops, wall stress, and the synchrony of LV segmental volume motions in patients with dilated cardiomyopathy. Background: Surgical LV volume reduction is under investigation as an alternative for, or bridge to, heart transplantation for patients with end-stage dilated cardiomyopathy. Methods: We measured P-V loops in eight patients with dil... Abstract
Cited 20 times since 2000 (0.8 per year) source: EuropePMC
American journal of respiratory and critical care medicine, Volume 162, Issue 2 Pt 1, 1 1 2000, Pages 374-379 Right ventricular function in respiratory distress syndrome and subsequent partial liquid ventilation. Homeometric autoregulation in the right ventricle of the newborn animal. Lopes Cardozo RH, Steendijk P, Baan J, Brouwers HA, De Vroomen M, Van Bel F
Infant respiratory distress syndrome (IRDS) and subsequent partial liquid ventilation (PLV) cause increased pulmonary vascular resistance, thus raising afterload. In nine newborn lambs the effects of IRDS and subsequent PLV on right (RV) and left ventricular (LV) contractility and systolic pump function were assessed using indices derived from RV and LV pressure-volume relations, obtained by micromanometric and conductance catheters during transient inferior vena cava occlusion. Pulmonary functi... Abstract
Cited 11 times since 2000 (0.5 per year) source: EuropePMC
Critical care medicine, Volume 28, Issue 5, 1 1 2000, Pages 1599-1606 Evaluation of a new transcardiac conductance method for continuous on-line measurement of left ventricular volume. Steendijk P, Lardenoye JW, van der Velde ET, Schalij MJ, Baan J
Objective: To evaluate a new, less invasive, conductance method to measure continuous on-line left ventricular volume. End-systolic and end-diastolic volumes obtained with this transcardiac conductance method were compared with simultaneous measurements using the conventional intracardiac conductance catheter. Design: Controlled animal study. Setting: Research laboratory in a university hospital. Subjects: Six sheep. Interventions: Anesthetized sheep were instrumented and inotropic condition was... Abstract
Cited 44 times since 2000 (1.8 per year) source: EuropePMC
Cardiovascular research, Volume 46, Issue 1, 1 1 2000, Pages 82-89 Comparison of intravenous and pulmonary artery injections of hypertonic saline for the assessment of conductance catheter parallel conductance. Steendijk P, Baan J
Objective: The conductance catheter provides a continuous measure of left ventricular volume. Conversion of raw data to calibrated absolute volume requires assessment of parallel conductance. Conventionally, parallel conductance is determined by injecting a small bolus hypertonic saline into the pulmonary artery and analyzing the signal obtained during passage of the bolus through the left ventricle. However, in some cases, a pulmonary artery catheter is not practicable. Therefore, we investigat... Abstract
Cited 1 times since 2000 (0 per year) source: EuropePMC
Biology of the neonate, Volume 78, Issue 2, 1 1 2000, Pages 98-105 Influence of inhibition of nitric oxide synthesis on cardiac function in the newborn lamb after hypoxic-ischemic injury. Dorrepaal CA, van Bel F, Steendijk P, Shadid M, van de Velde ET, Moison RM, Berger HM, Baan J
The aim of the present study was to investigate the effect of immediate post-hypoxic-ischemic (HI) inhibition of nitric oxide synthesis by N(omega)-nitro-L-arginine (NLA) on cardiac function and reactive oxygen species production. Fifteen newborn lambs were subjected to severe HI. Upon resuscitation 5 received 10 mg NLA/kg, 4 40 mg NLA/kg and 6 a placebo. Left ventricular (LV) contractility, cardiac output (CO), non-protein-bound iron (NPBI), ratio of reduced/oxidized ascorbic acid, alpha-tocoph... Abstract
Cited 48 times since 2000 (2 per year) source: EuropePMC
American journal of physiology. Heart and circulatory physiology, Volume 278, Issue 1, 1 1 2000, Pages H100-5 Improved contractile performance of right ventricle in response to increased RV afterload in newborn lamb. de Vroomen M, Cardozo RH, Steendijk P, van Bel F, Baan J
Pulmonary hypertension results in an increased afterload for the right ventricle (RV). To determine the effects of this increased afterload on RV contractile performance, we examined RV performance before and during 4 h of partial balloon occlusion of the pulmonary artery and again after releasing the occlusion in nine newborn lambs. RV contractile performance was quantified by indexes derived from systolic RV pressure-volume relations obtained by a combined pressure-conductance catheter during... Abstract
Cited 6 times since 1999 (0.2 per year) source: EuropePMC
Early human development, Volume 55, Issue 3, 1 1 1999, Pages 237-245 Electrocortical brain activity during hypoxia and hypotension in anesthetized newborn lambs. van de Bor M, Meinesz J, Benders MJ, Steendijk P, Lopes Cardozo RH, van Bel F
Blood gas and blood pressure disturbances do influence cerebral blood flow in newborns. To what extent cerebral blood flow changes affect electrocortical brain activity remains uncertain. We studied the effect of severe hypoxia and hemorrhagic hypotension on carotid artery blood flow and electrocortical brain activity in newborn anesthetized lambs. During hypoxia carotid artery blood flow increased significantly, whereas electrocortical brain activity remained unchanged. The hemorrhagic hypotens... Abstract
Cited 12 times since 1999 (0.5 per year) source: EuropePMC
Cardiovascular research, Volume 43, Issue 1, 1 1 1999, Pages 86-95 Right ventricular systolic function and ventricular interaction during acute embolisation of the left anterior descending coronary artery in sheep. Jerzewski A, Steendijk P, Pattynama PM, Leeuwenburgh BP, de Roos A, Baan J
Objective: Regional LV ischemia involving the septum affects LV systolic function and geometry. We investigated the effects of these changes on RV function and geometry. Methods: In six closed-chest sheep end-systolic pressure-volume relationships (ESPVRs) were constructed from ventricular volumes, measured with magnetic resonance imaging (MRI) and matching intraventricular pressures, before and after selective embolisation of the left anterior descending coronary artery (LAD). The extent of myo... Abstract
Cited 6 times since 1999 (0.2 per year) source: EuropePMC
Basic research in cardiology, Volume 94, Issue 1, 1 1 1999, Pages 23-30 Pretreatment with allopurinol in cardiac hypoxic-ischemic reperfusion injury in newborn lambs exerts its beneficial effect through afterload reduction. Shadid M, Van Bel F, Steendijk P, Dorrepaal CA, Moison R, Van der Velde ET, Baan J
The aim of this study was to determine whether allopurinol (ALLO) reduces reperfusion injury inflicted upon the heart resulting from excess production of free oxygen radicals after hypoxia and ischemia (HI) in newborn animals. We, therefore, produced severe HI in 13 newborn lambs by low O2-ventilation and blood volume reduction. One hour before HI seven lambs received ALLO (20 mg/kg i.v.), six received a placebo (CONT). Cardiac function and hemodynamic parameters were assessed by sequential meas... Abstract
Cited 1 times since 1999 (0 per year) source: EuropePMC
Biology of the neonate, Volume 75, Issue 2, 1 1 1999, Pages 130-136 Effect of exchange transfusion on brain perfusion and electrocortical brain activity in newborn lambs. Benders MJ, Meinesz JH, Dorrepaal CA, Steendijk P, van Bel F, van de Bor M
Changes in brain perfusion (using ultrasonic-determined changes in carotid artery blood flow: Qcar) and electrocortical brain activity (ECBA, obtained by a Lectromed cerebral function monitor) were studied during exchange transfusion using the push-pull method in the newborn lamb. Changes in mean arterial blood pressure (MABP), Qcar, heart rate (HR), and ECBA were observed during all exchange transfusions: MABP, Qcar, and ECBA decreased during the withdrawal period and increased during the infus... Abstract