Peripheral chemoreflex sensitivity in patients with heart failure and preserved inspiratory muscle strength

Abstract

Individuals with chronic heart failure (CHF) and inspiratory muscle weakness exhibit na exacerbated peripheral chemoreflex sensitivity (PCS) in relation to patients with preserved inspiratory muscle strength. However, it remains unclear wether patients with CHF patients with preserved inspiratory muscle strength show PCS similar to healthy individuals. The objective of this study was to compare PCS between patients with CHF and preserved inspiratory muscle strength and healthy individuals. Ten subjects with CHF (55 ± 8 years old) and 10 healthy subjects (54 ± 7 years old) matched for sex and age participated in this study. All subjects showed preserved inspiratory muscle strength, which was measured through a pressure transducer. PCS was obtained through the technique of transient hypoxia induced by the inhalation of pure nitrogen, which was repeated for 10 times. PCS was calculated by linear regression analysis between maximal ventilation and lower oxygen saturation. PCS in patients with CHF and preserved inspiratory muscle strength (1.09 ± 0.95 L.min −1 .% SaO 2 −1 ) did not differ from healthy subjects (0.70 ± 0.73 L.min −1 .% SpO 2 −1 ; P = 0.31). There was a significant association between PCS and inspiratory muscle strength ( r = 0.58, P = 0.006), however only 19% of variance in PCS may be explained by inspiratory muscle strength. Patients with CHF and preserved inspiratory muscle strength show PCS similar to healthy individuals.