Anton Vonk-Noordegraaf

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Survival in patients with pulmonary arterial hypertension (PAH) is closely related to right ventricular (RV) function. Although pulmonary load is an important determinant of RV systolic function in PAH, there remains a significant variability in RV adaptation to pulmonary hypertension. In this report, the authors discuss the emerging concepts of right heart(More)
OBJECTIVES The purpose of this study was to examine the relationship between changes in pulmonary vascular resistance (PVR) and right ventricular ejection fraction (RVEF) and survival in patients with pulmonary arterial hypertension (PAH) under PAH-targeted therapies. BACKGROUND Despite the fact that medical therapies reduce PVR, the prognosis of patients(More)
PURPOSE To assess the accuracy of several noninvasive MRI-based estimators of pulmonary artery pressure by comparing them with invasive pressure measurement. MATERIALS AND METHODS We compared five MRI methods with invasive pressure measurement by catheterization, in one group of pulmonary hypertension (PH) patients. Doppler echocardiography was included(More)
Right ventricular (RV) afterload is commonly defined as pulmonary vascular resistance, but this does not reflect the afterload to pulsatile flow. The purpose of this study was to quantify RV afterload more completely in patients with and without pulmonary hypertension (PH) using a three-element windkessel model. The model consists of peripheral resistance(More)
BACKGROUND Data on the effect of initial combination therapy with ambrisentan and tadalafil on long-term outcomes in patients with pulmonary arterial hypertension are scarce. METHODS In this event-driven, double-blind study, we randomly assigned, in a 2:1:1 ratio, participants with World Health Organization functional class II or III symptoms of pulmonary(More)
AIMS Decreased total compliance of the pulmonary vascular bed is associated with increased mortality in patients with pulmonary arterial hypertension (PAH). We investigated whether proximal pulmonary artery stiffness, in terms of area distensibility and noninvasively assessed relative area change (RAC), calculated as relative cross-sectional area change,(More)
AIMS Pulmonary arterial compliance (C) is increasingly being recognized as an important contributor to right ventricular afterload, but for monitoring of treatment of pulmonary hypertension (PH) most often still only pulmonary vascular resistance (R) is used. We aimed at testing the hypothesis that R and C are coupled during treatment of PH and that(More)
OBJECTIVES The purpose of this study was to explore in pulmonary arterial hypertension (PAH) whether the cause of interventricular asynchrony lies in onset of shortening or duration of shortening. BACKGROUND In PAH, leftward ventricular septal bowing (LVSB) is probably caused by a left-to-right (L-R) delay in myocardial shortening. METHODS In 21 PAH(More)
RATIONALE Recently it was suggested that patients with pulmonary hypertension (PH) suffer from inspiratory muscle dysfunction. However, the nature of inspiratory muscle weakness in PH remains unclear. OBJECTIVES To assess whether alterations in contractile performance and in morphology of the diaphragm underlie inspiratory muscle weakness in PH. METHODS(More)
BACKGROUND The role of right ventricular (RV) diastolic stiffness in pulmonary arterial hypertension (PAH) is not well established. Therefore, we investigated the presence and possible underlying mechanisms of RV diastolic stiffness in PAH patients. METHODS AND RESULTS Single-beat RV pressure-volume analyses were performed in 21 PAH patients and 7 control(More)