Influence of bronchial blood flow and conductance on pulmonary function in stable systolic heart failure

Abstract

Background The aim of this study was to determine the relationship between airway blood flow View the MathML source, airway conductance (Gf-aw) and pulmonary function in patients with stable HF. Methods 12 controls (CTRL: age = 63 ᠹ years, FVC = 98 ᠱ5%pred, LVEF = 61 ᠶ%) (all data presented as mean ᠓D), 16 patients with mild HF (HF-A, NYHA I-II: age = 64 ᠹ years, FVC = 90 ᠱ7%pred, LVEF = 28 ᠶ%), and 14 patients with moderate/severe HF (HF-B, NYHA III-IV: age = 65 ᠶ years, FVC = 84 ᠱ2%pred, LVEF = 26 ᠶ%) were studied. View the MathML source was assessed using soluble gas measurements; perfusion pressure across airway bed (?Paw) was estimated from systemic and pulmonary pressure measurements; Gf-aw was calculated as View the MathML source; PF was assessed by spirometry. Results While View the MathML source was not significantly different between CTRL (61.3 ᠱ7.9 匠min-1 mL-1), HF-A (70.1 ᠲ6.9 匠min-1 mL-1) and HF-B (56.2 ᠱ4.9 匠min-1 mL-1) groups, Gf-aw, was elevated in HF-A (1.1 ᠰ.4 匠min-1 mL-1 mmHg-1, p < 0.03) and tended to be elevated in HF-B (1.2 ᠰ.6 匠min-1 mL-1 mmHg-1, p = 0.07) when compared to CTRL (0.8 ᠰ.3 匠min-1 mL-1 mmHg-1). Significant positive correlations were found between Gf-aw and RV/TLC for HF-A (r = 0.63, p < 0.02) and HF-B (r = 0.58, p < 0.05). Conclusions These results support the hypothesis that increased bronchial conductance and bronchial congestion may be related to greater small airway obstruction and as such may play a role in the PF abnormalities and symptoms of congestion commonly observed in HF patients.