Ventilatory constraints influence physiological dead space in heart failure

New FindingsWhat is the central question of this study?The goal of this study was to investigate the effect of alterations in tidal volume and alveolar volume on the elevated physiological dead space and the contribution of ventilatory constraints thereof in heart failure patients during submaximal exercise.What is the main finding and its importance?We found that physiological dead space was elevated in heart failure via reduced tidal volume and alveolar volume. Furthermore, the degree of ventilatory constraints was associated with physiological dead space and alveolar volume.AbstractPatients who have heart failure with reduced ejection fraction (HFrEF) exhibit impaired ventilatory efficiency [i.e. greater ventilatory equivalent for carbon dioxide () slope] and elevated physiological dead space (VD/VT). However, the impact of breathing strategy onVD/VT during submaximal exercise in HFrEF is unclear. The HFrEF (n = 9) and control (CTL,n = 9) participants performed constant‐load cycling exercise at similar ventilation (). Inspiratory capacity, operating lung volumes and arterial blood gases were measured during submaximal exercise. Arterial blood gases were used to deriveVD/VT, alveolar volume, dead space volume, alveolar ventilation and dead space ventilation. During submaximal exercise, HFrEF patients had greater slope andVD/VT than CTL subjects (P = 0.01). At similar , HFrEF patients had smaller tidal volumes and alveolar volumes (HFrEF 1.11 ± 0.33 litresversus CTL ...
Source: Experimental Physiology - Category: Physiology Authors: Tags: RESEARCH PAPER Source Type: research