In JoVE (1)

Other Publications (18)

Articles by Harm Jan Bogaard in JoVE

Other articles by Harm Jan Bogaard on PubMed

Diaphragm Muscle Fiber Weakness in Pulmonary Hypertension

American Journal of Respiratory and Critical Care Medicine. May, 2011  |  Pubmed ID: 21131469

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.

Progressive Right Ventricular Dysfunction in Patients with Pulmonary Arterial Hypertension Responding to Therapy

Journal of the American College of Cardiology. Dec, 2011  |  Pubmed ID: 22133851

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.

Progressive Changes in Right Ventricular Geometric Shortening and Long-term Survival in Pulmonary Arterial Hypertension

Chest. Apr, 2012  |  Pubmed ID: 21960697

Until now, many investigators have focused on describing right ventricular (RV) dysfunction in groups of patients with pulmonary arterial hypertension (PAH), but very few have addressed the deterioration of RV function over time. The aim of this study was to investigate time courses of RV geometric changes during the progression of RV failure.

Right Atrial Pressure Affects the Interaction Between Lung Mechanics and Right Ventricular Function in Spontaneously Breathing COPD Patients

PloS One. 2012  |  Pubmed ID: 22272306

It is generally known that positive pressure ventilation is associated with impaired venous return and decreased right ventricular output, in particular in patients with a low right atrial pressure and relative hypovolaemia. Altered lung mechanics have been suggested to impair right ventricular output in COPD, but this relation has never been firmly established in spontaneously breathing patients at rest or during exercise, nor has it been determined whether these cardiopulmonary interactions are influenced by right atrial pressure.

Spirometry in Chronic Obstructive Pulmonary Disease: a Hemodynamic Roller Coaster?

American Journal of Respiratory and Critical Care Medicine. Aug, 2012  |  Pubmed ID: 22896598

Cardiopulmonary Exercise Testing Reveals Onset of Disease and Response to Treatment in a Case of Heritable Pulmonary Arterial Hypertension

Pulmonary Circulation. Jul, 2012  |  Pubmed ID: 23130108

Patients affected by pulmonary arterial hypertension (PAH) show a typical pattern of abnormalities on cardiopulmonary exercise testing (CPET). However, CPET is not routinely used as a screening method. We discuss a patient with hereditary PAH in whom CPET revealed onset of disease. Furthermore, we show that the abnormalities observed can improve in part by PAH-specific treatment.

Thyroid Hormone is Highly Permissive in Angioproliferative Pulmonary Hypertension in Rats

The European Respiratory Journal. Jan, 2013  |  Pubmed ID: 22835607

Epidemiological evidence links pulmonary arterial hypertension (PAH) with thyroid disease, but a mechanistic explanation for this association is lacking. Because a central hallmark of vascular remodelling in pulmonary hypertension is lumen obliteration by endothelial cell growth and because thyroid hormones are known to be angiogenic, we hypothesised that thyroid hormones play a role in the control of endothelial cell proliferation in experimental PAH in rats. Hypothyroidism was induced by subtotal thyroidectomy and treatment with propylthiouracil (PTU) in rats with experimental PAH after combined exposure to vascular endothelial growth factor receptor inhibition and hypoxia (the Sugen-chronic hypoxia (SuHx) model). Subtotal thyroidectomy prevented and PTU treatment reversed the development of severe experimental PAH. Thyroxin repletion restored the PAH phenotype in thyroidectomised SuHx rats. The prevention of PAH by thyroidectomy was associated with a reduced rate of cell turnover, reduced extracellular signal-regulated protein kinases 1 and 2 phosphorylation, and reduced expression of α(v)β(3) integrin, fibroblast growth factor (FGF)-2 and FGF receptor. Thyroidectomy mitigated hypoxia-induced pulmonary hypertension, but this effect was not associated with a decreased pulmonary vascular resistance. These data suggest that thyroid hormone permits endothelial cell proliferation in PAH. A causal link between thyroid diseases and the onset or progression of vascular remodelling in PAH patients remains to be determined.

Author's Reply

Pulmonary Circulation. Jan, 2013  |  Pubmed ID: 23662185

Severely Reduced Diffusion Capacity in Idiopathic Pulmonary Arterial Hypertension: Patient Characteristics and Treatment Responses

The European Respiratory Journal. Dec, 2013  |  Pubmed ID: 23949959

A subgroup of patients with idiopathic pulmonary arterial hypertension (IPAH) has severely reduced diffusing capacity of the lung for carbon monoxide (DLCO) and poor prognosis. Their characteristics are currently unknown. The aim of this study is to contrast clinical characteristics and treatment responses of IPAH-patients with a severely reduced and more preserved DLCO. Retrospectively, 166 IPAH patients were included and grouped based on a DLCO cut-off value of 45% pred (IPAH(<45%) and IPAH(≥45%)). Clinical characteristics, treatment responses and survival were compared. IPAH(<45%) were older, more often male, had a more frequent history of coronary disease and a higher tobacco exposure. Forced expiratory volume in 1 s (FEV1), FEV1/forced vital capacity, total lung capacity and alveolar volume values were slightly lower and computed tomography scan abnormalities more prevalent in patients with a low DLCO. Age and number of pack years were independently associated with DLCO < 45% pred. IPAH(<45%) showed no different haemodynamic profile, yet worse exercise performance and a worse survival rate, which were both related to age, sex and the presence of coronary disease. To conclude, a severely reduced DLCO in IPAH is associated with advanced age and a greater tobacco exposure. These patients have a worse exercise performance despite a similar hemodynamic profile. We confirm the decreased survival in this patient group and now show that this poor outcome is related to age, sex and the presence of coronary disease.

Pulmonary Arterial Hypertension Combined with a High Cardiac Output State: Three Remarkable Cases

Pulmonary Circulation. Apr, 2013  |  Pubmed ID: 24015348

A congenital extrahepatic portosystemic venous shunt (CEPVS), also known as an Abernethy malformation, is a rare cause of pulmonary arterial hypertension (PAH). In this case series, we describe three male patients of 30, 23, and 27 years of age with PAH due to a CEPVS. In all three patients, a right heart catheterization revealed a high cardiac output. The aim of this case series is to make pulmonary hypertension physicians aware of the possibility of a CEPVS when PAH is accompanied with a high cardiac output state.

Diffusion Capacity and BMPR2 Mutations in Pulmonary Arterial Hypertension

The European Respiratory Journal. Sep, 2013  |  Pubmed ID: 24036241

Experimental Models of Right Heart Failure: a Window for Translational Research in Pulmonary Hypertension

Seminars in Respiratory and Critical Care Medicine. Oct, 2013  |  Pubmed ID: 24037635

The right ventricle (RV) faces major changes in loading conditions associated with cardiovascular and pulmonary vascular disorders. Despite major pharmacological advances since the last decade, pulmonary arterial hypertension remains a deadly disease mainly secondary to the development of right ventricular failure (RVF). Several experimental models of RVF have been developed over the past three decades providing a particular insight in RV pathophysiology. Mechanisms involved in the transition from RV adaptive hypertrophy to maladaptive remodeling and failure in conditions of chronic RV pressure or volume overload are of a great interest but not yet completely understood. Further investigations are needed to find new therapeutic approaches for RVF. Current animal models and emerging concepts of translational RV research will be detailed in this review.

Risk Factors for Hemoptysis in Idiopathic and Hereditary Pulmonary Arterial Hypertension

PloS One. 2013  |  Pubmed ID: 24194909

When hemoptysis complicates pulmonary arterial hypertension (PAH), it is assumed to result from bronchial artery hypertrophy. In heritable PAH, the most common mutation is in the BMPR2 gene, which regulates growth, differentiation and apoptosis of mesenchymal cells. The aim of this study is to determine the relationship in PAH between the occurrence of hemoptysis, and disease progression, bronchial artery hypertrophy, pulmonary artery dilation and BMPR2 mutations.

The Right Ventricle Explains Sex Differences in Survival in Idiopathic Pulmonary Arterial Hypertension

Chest. Dec, 2013  |  Pubmed ID: 24306900

Male sex is an independent predictor of worse survival in pulmonary arterial hypertension (PAH). This finding might be explained by more severe pulmonary vascular disease, worse right ventricular function or different response to therapy. The aim of this study was to investigate the underlying cause of sex differences in survival in treated PAH patients.

Definitions and Diagnosis of Pulmonary Hypertension

Journal of the American College of Cardiology. Dec, 2013  |  Pubmed ID: 24355641

Pulmonary hypertension (PH) is defined by a mean pulmonary artery pressure ≥ 25 mm Hg at rest, measured during right heart catheterization. There is still insufficient evidence to add an exercise criterion to this definition. The term pulmonary arterial hypertension (PAH) describes a subpopulation of patients with PH characterized hemodynamically by the presence of pre-capillary PH including an end-expiratory pulmonary artery wedge pressure (PAWP) ≤ 15 mm Hg and a pulmonary vascular resistance >3 Wood units. Right heart catheterization remains essential for a diagnosis of PH or PAH. This procedure requires further standardization, including uniformity of the pressure transducer zero level at the midthoracic line, which is at the level of the left atrium. One of the most common problems in the diagnostic workup of patients with PH is the distinction between PAH and PH due to left heart failure with preserved ejection fraction (HFpEF). A normal PAWP does not rule out the presence of HFpEF. Volume or exercise challenge during right heart catheterization may be useful to unmask the presence of left heart disease, but both tools require further evaluation before their use in general practice can be recommended. Early diagnosis of PAH remains difficult, and screening programs in asymptomatic patients are feasible only in high-risk populations, particularly in patients with systemic sclerosis, for whom recent data suggest that a combination of clinical assessment and pulmonary function testing including diffusion capacity for carbon monoxide, biomarkers, and echocardiography has a higher predictive value than echocardiography alone.

The Importance of Trabecular Hypertrophy in Right Ventricular Adaptation to Chronic Pressure Overload

The International Journal of Cardiovascular Imaging. Feb, 2014  |  Pubmed ID: 24306052

To assess the contribution of right ventricular (RV) trabeculae and papillary muscles (TPM) to RV mass and volumes in controls and patients with pulmonary arterial hypertension (PAH). Furthermore, to evaluate whether TPM shows a similar response as the RV free wall (RVFW) to changes in pulmonary artery pressure (PAP) during follow-up. 50 patients underwent cardiac magnetic resonance (CMR) and right heart catheterization at baseline and after one-year follow-up. Furthermore 20 controls underwent CMR. RV masses were assessed with and without TPM. TPM constituted a larger proportion of total RV mass and RV end-diastolic volume (RVEDV) in PAH than in controls (Mass: 35 ± 7 vs. 25 ± 5 %; p < 0.001; RVEDV: 17 ± 6 vs. 12 ± 6 %; p = 0.003). TPM mass was related to the RVFW mass in patients (baseline: R = 0.65; p < 0.001; follow-up: R = 0.80; p < 0.001) and controls (R = 0.76; p < 0.001). In PAH and controls, exclusion of TPM from the assessment resulted in altered RV mass, volumes and function than when included (all p < 0.01). Changes in RV TPM mass (β = 0.44; p = 0.004) but not the changes in RVFW mass (p = 0.095) were independently related to changes in PAP during follow-up. RV TPM showed a larger contribution to total RV mass in PAH (~35 %) compared to controls (~25 %). Inclusion of TPM in the analyses significantly influenced the magnitude of the RV volumes and mass. Furthermore, TPM mass was stronger related to changes in PAP than RVFW mass. Our results implicate that TPM are important contributors to RV adaptation during pressure overload and cannot be neglected from the RV assessment.

Pulmonary Arterial Hypertension Preceding Idiopathic Pulmonary Fibrosis in a BMPR2 Mutation Positive Patient

European Respiratory Review : an Official Journal of the European Respiratory Society. Mar, 2014  |  Pubmed ID: 24591673

Assessment of Right Ventricular Responses to Therapy in Pulmonary Hypertension

Drug Discovery Today. Mar, 2014  |  Pubmed ID: 24637045

Irrespective of its cause, pulmonary hypertension (PH) leads to an increase in pulmonary vascular resistance (PVR). Failing adaption of the right ventricle (RV) to the increased afterload is the main cause of death in PH patients and therefore monitoring RV function during treatment is essential. However, consensus on the optimal method for serial assessment of RV function is lacking and therefore the major clinical trials on PH-specific therapies have not provided clear answers with respect to the response of the RV to treatment. This short review will give an overview of the most important load-dependent and load-independent parameters for assessing RV response to therapy in PH patients.

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