[Dynamic hyperinflation in pulmonary arterial hypertension: "hyperinflator" and "non-hyperinflator"]. / Dynamische Hyperinflation bei der pulmonal arteriellen Hypertonie: "Hyperinflator" und "Non-Hyperinflator".

BACKGROUND: The dynamic decrease in inspiratory capacity (IC) during exercise with restriction of tidal volume (VT) is known as dynamic hyperinflation (DH) and is described mostly in patients with COPD differentiating between a "hyperinflator" and a "non-hyperinflator". Recent studies have revealed DH in patients with idiopathic pulmonary arterial hypertension (iPAH), but the influence of the DH on the reduced exercise capacity with exertional dyspnoae is still being debated. METHODS: We analysed flow-volume curves during cardiopulmonary exercise testing (CPET) in idiopathic PAH (n = 19), in COPD (n = 17), in idiopathic pulmonary fibrosis (IPF) (n = 19) and a control group (n = 30). We measured IC at rest and during maximal exercise and furthermore ventilation, VT and oxygen uptake (VO2 peak). In iPAH a right heart catheter test and a 6-minute walk test (6MWT) were performed, also the B-type naturetic peptide (BNP) and the NYHA/WHO functional class were determined. RESULTS: The IC decreased significantly in 11 PAH "hyperinflators" (PAH-H) (Δ IC: - 0.34 ± 0.14 L, p < 0.001) compared to 8 PAH "non-hyperinflators" (PAH-NH) (Δ IC: 0.08 ± 0.2 L). COPD patients exhibited a characteristic hyperinflation pattern with a decrease in IC throughout exercise (Δ IC: - 0.61 ± 0.3 L, p < 0.001), while patients with IPF (Δ IC: 0.03 ± 0.15 L) and the control group responsed to exercise with a non-hyperinflator pattern (Δ IC: 0.1 ± 0.2 L). Both PAH collectives showed a reduced IC/TLC, while VT/IC was elevated with a decreased peak VO2 and max. performance compared to the control group. Correlations of the IC rest/max (L) were shown in PAH-H and PAH-NH with the VO2 peak, max. performance and VT. CONCLUSION: The analysis of flow-volume curves during CPET can indentify DH in a subgroup of patients with iPAH. The DH contributes significantly but slightly to the development of exertional limitations and dyspnoe in a subgroup of iPAH. Further studies with a larger sample size will be required to definitively measure the impact of the DH seen in these patients.

[Obstructive sleep apnea and stroke]. / Obstruktive Schlaf-Apnoe und Schlaganfall.

More than half of the patients hospitalised with stroke suffer from sleep-disordered breathing and 5 - 10 % of patients with newly diagnosed obstructive sleep apnea (OSA) have a history of stroke. Epidemiological studies have shown that untreated OSA is an independent risk factor for stroke. Various pathophysiological mechanisms may contribute to the development of stroke in these patients (i. e., OSA-associated arterial hypertension, atherosclerosis, atrial fibrillation, paradoxical embolism through a patent foramen ovale and disturbed cerebrovascular reactivity). Co-existent OSA has a negative impact on both the recovery of neurological functions and the survival of patients with stroke. On the other hand, CPAP therapy has beneficial effects on the incidence and recurrence of stroke in OSA and also on the clinical outcome of those patients who are victims of stroke.

[Pulmonary hypertension: hemodynamic evaluation: hemodynamic evaluation ­ recommendations of the Cologne Consensus Conference 2010]. / Pulmonale Hypertonie: invasive Diagnostik: Empfehlungen der Kölner Konsensus-Konferenz 2010.

The 2009 European Guidelines on Diagnosis and Treatment of Pulmonary Hypertension (PH) have been adopted for Germany. Invasive hemodynamic data obtained by right heart catheterization are essential to confirm the diagnosis, test vasoreactivity, assess severity and guide therapy in PH patients. The definition of PH is resting on a mean pulmonary artery pressure ≥ 25 mm Hg obtained by right heart catheterization. Furthermore, a pulmonary capillary wedge pressure > 15 mm Hg excludes pre-capillary PH. Vasoreactivity testing is part of the diagnostic work-up in pulmonary arterial hypertension. Recent data on the use of inhaled iloprost update these guidelines and are of special importance due to the frequent diagnostic use of iloprost in Germany. Other aspects of invasive hemodynamic data in certain PH subgroups as well as their measurement and interpretation in children are discussed. Several aspects of right heart catheterization in PH justify a detailed commentary, and in some areas an update already appears necessary. In June 2010, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Paediatric Cardiology (DGPK) was held in Cologne, Germany. This conference aimed to solve practical and controversial issues surrounding the implementation of the European Guidelines in Germany. To this end, a number of working groups were initiated, one of which was specifically addressing the invasive hemodynamic evaluation of patients with PH. This commentary summarizes the results and recommendations of this working group.