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Background: The effect of pulmonary hypertension (PH) on right ventricular (RV) afterload is commonly defined by elevation of pulmonary artery (PA) pressure or pulmonary vascular resistance (PVR). In humans however, one-third to half of the hydraulic power in the PA is contained in pulsatile components of flow. Pulmonary impedance (Zc) expresses opposition of the PA to pulsatile blood flow. We evaluate pulmonary Zc relationships according to PH classification using a cardiac magnetic resonance (CMR)/right heart catheterization (RHC) method.
Methods: Prospective study of 70 clinically indicated patients referred for same-day CMR and RHC [60 ± 16 years; 77% females, 16 mPAP <25 mmHg (PVR <240 dynes.s.cm /mPCWP <15 mmHg), 24 pre-capillary (PrecPH), 15 isolated post-capillary (IpcPH), 15 combined pre-capillary/post-capillary (CpcPH)]. CMR provided assessment of PA flow, and RHC, central PA pressure. Pulmonary Zc was expressed as the relationship of PA pressure to flow in the frequency domain (dynes.s.cm ).
Results: Baseline demographic characteristics were well matched. There was a significant difference in mPAP (P < 0.001), PVR (P = 0.001), and pulmonary Zc between mPAP<25 mmHg patients and those with PH (mPAP <25 mmHg: 47 ± 19 dynes.s.cm ; PrecPH 86 ± 20 dynes.s.cm ; IpcPH 66 ± 30 dynes.s.cm ; CpcPH 86 ± 39 dynes.s.cm ; P = 0.05). For all patients with PH, elevated mPAP was found to be associated with raised PVR (P < 0.001) but not with pulmonary Zc (P = 0.87), except for those with PrecPH (P < 0.001). Elevated pulmonary Zc was associated with reduced RVSWI, RVEF, and CO (all P < 0.05), whereas PVR and mPAP were not.
Conclusions: Raised pulmonary Zc was independent of elevated mPAP in patients with PH and more strongly predictive of maladaptive RV remodelling than PVR and mPAP. Use of this straightforward method to determine pulmonary Zc may help to better characterize pulsatile components of RV afterload in patients with PH than mPAP or PVR alone.
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http://dx.doi.org/10.1002/ehf2.14180 | DOI Listing |
PLoS One
September 2025
Department of Anesthesiology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou, China.
Purpose: Uncertainty persists regarding the optimal mode of mechanical ventilation for laparoscopic perioperative periods. Electrical impedance tomography (EIT) is an effective tool for monitoring and guiding lung-protective ventilation. This study aimed to compare the effects of pressure-controlled ventilation-volume guaranteed (PCV-VG) and volume-controlled ventilation (VCV) on pulmonary ventilation during laparoscopic surgery.
View Article and Find Full Text PDFAim: Positive expiratory pressure devices are frequently used for airway clearance in children with cystic fibrosis and tracheobronchomalacia. This study aimed to establish if electrical impedance tomography is a feasible measure to titrate pressures in non-sedated children.
Method: Ten children with cystic fibrosis and tracheobronchomalacia performed airway clearance using positive pressure devices whilst monitored with electrical impedance tomography.
Front Physiol
August 2025
School of Mechanical Engineering and IEDT, Kyungpook National University, Daegu, Republic of Korea.
Introduction: Quantitative computed tomography (qCT) provides detailed spatial assessments of lung structure and function, while electrical impedance tomography (EIT) offers high temporal resolution for analyzing breathing patterns but lacks structural detail. This study investigates the correlation between qCT-based spatial variables and EIT-based temporal signals to elucidate the physiological relationships between these two modalities.
Methods: Six participants with asthma underwent pulmonary function tests (PFTs) before and after bronchodilator inhalation.
Gastro Hep Adv
June 2025
Leeds Institute of Medical Research, University of Leeds, Leeds, UK.
Background And Aims: Gastroesophageal reflux (GER) is common and thought to contribute to disease progression in patients with respiratory disease. Delayed gastric emptying (DGE) can increase GER in patients with GER disease, but its effect in patients with respiratory disease, and how differing lung structure (eg, scarring, inflammation) and mechanics (eg, decreased thoracic pressure in restrictive disease, increased abdominal pressure in obstructive disease) influences this is unknown. Our aim was to understand these interrelationships and association with pulmonary function in patients with chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF) and non-IPF interstitial lung disease (non-IPF ILD).
View Article and Find Full Text PDFComput Methods Programs Biomed
September 2025
School of Biological Sciences and Medical Engineering, Southeast University, Nanjing, Jiangsu, China. Electronic address:
Background And Objective: The quantitative knowledge of the influence of the small airway disease on the functional changes in chronic obstructive pulmonary disease (COPD) patients has been severely limited.
Methods: This study presents an innovative patient-specific computational framework that integrates CT and OCT imaging data with multiscale computational fluid dynamics (CFD) analysis. A three-dimensional tracheobronchial tree is reconstructed from CT scans of a mild COPD patient, spanning from the central airway to the 4th generation bronchial bifurcations.