Effects of 5-Week Oral Acetazolamide on Incremental Cycling Exercise in Pulmonary Arterial and Chronic Thromboembolic Pulmonary Hypertension: A Randomized Placebo-Controlled, Double-Blinded, Crossover Trial.

Introduction: Acetazolamide (AZA) improves nocturnal and daytime blood oxygenation in patients with pulmonary vascular disease (PVD), defined as pulmonary arterial and distal chronic thromboembolic pulmonary hypertension (CTEPH), and may improve exercise performance.

Methods: We investigated the effect of 5 weeks of AZA (250 mg bid) versus placebo on maximal load during incremental cycling ramp exercise in patients with PVD studied in a randomized controlled, double-blind, crossover design, separated by > 2 weeks of washout.

Results: Twenty-five patients (12 pulmonary arterial hypertension, 13 CTEPH, 40% women, age 62 ± 15 years) completed the trial according to the protocol.

[Vaskuläre Dyspnoe: Pulmonale Hypertonie].

Pulmonary hypertension (PH) is defined by a mean pulmonary artery pressure > 20 mmHg [1] [2]. Echocardiography is used to screen for pulmonary hypertension, but right heart catheterization is required to confirm the diagnosis. Right heart catheterization is used to measure hemodynamic parameters such as pulmonary arterial pressures and pulmonary artery wedge pressure (PAWP), which normally corresponds to the left ventricular end-diastolic pressure.

Effects of Acute Hypoxia on Heart Rate Variability in Patients with Pulmonary Vascular Disease.

Pulmonary vascular diseases (PVDs), defined as arterial or chronic thromboembolic pulmonary hypertension, are associated with autonomic cardiovascular dysregulation. Resting heart rate variability (HRV) is commonly used to assess autonomic function. Hypoxia is associated with sympathetic overactivation and patients with PVD might be particularly vulnerable to hypoxia-induced autonomic dysregulation.

Effect of 5 weeks of oral acetazolamide on patients with pulmonary vascular disease: A randomized, double-blind, cross-over trial.

Background: The carbonic anhydrase inhibitor acetazolamide stimulates ventilation through metabolic acidosis mediated by renal bicarbonate excretion. In animal models, acetazolamide attenuates acute hypoxia-induced pulmonary hypertension (PH), but its efficacy in treating patients with PH due to pulmonary vascular disease (PVD) is unknown.

Methods: 28 PVD patients (15 pulmonary arterial hypertension, 13 distal chronic thromboembolic PH), 13 women, mean±SD age 61.

Cardiorespiratory Adaptation to Short-Term Exposure to Altitude vs. Normobaric Hypoxia in Patients with Pulmonary Hypertension.

Prediction of adverse health effects at altitude or during air travel is relevant, particularly in pre-existing cardiopulmonary disease such as pulmonary arterial or chronic thromboembolic pulmonary hypertension (PAH/CTEPH, PH). A total of 21 stable PH-patients (64 ± 15 y, 10 female, 12/9 PAH/CTEPH) were examined by pulse oximetry, arterial blood gas analysis and echocardiography during exposure to normobaric hypoxia (NH) (FiO2 15% ≈ 2500 m simulated altitude, data partly published) at low altitude and, on a separate day, at hypobaric hypoxia (HH, 2500 m) within 20−30 min after arrival. We compared changes in blood oxygenation and estimated pulmonary artery pressure in lowlanders with PH during high altitude simulation testing (HAST, NH) with changes in response to HH.