Activation of the ergoreceptors in cardiac patients with and without heart failure

Abstract

Background: The presence of ergoreflex activity and its current relationship to hyperventilation and prognosis in cardiac patients is unclear. Therefore, we evaluated ergoreflex activity in cardiac patients with and without heart failure (CHF) as well as in healthy subjects, and we examined how ergoreceptor activity was related to a mortality risk score in CHF (MAGGIC).

Methods and results: Twenty-five healthy subjects and 76 patients were included, among whom were 25 with ischemic heart disease (IHD), 24 with stable CHF, and 27 with unstable CHF. Ergoreflex activity was measured with a dynamic handgrip exercise, followed by post-handgrip regional circulatory occlusion (PH-RCO). Ergoreflex activity contributed significantly to ventilation (median [interquartile range] %V) in unstable CHF (81 [73-91] %V without PH-RCO, 92 [82-107] %V with PH-RCO, and 11 [6-20] difference in %V; P < .001) and was positively correlated with the MAGGIC risk score (Spearman ρ = 0.431; P = .002). No ergoreflex activity was observed in healthy subjects (-4 [-10 to 5] difference in %V), IHD (0 [-8 to 3] Diff in %V) and stable CHF (-3 [-11 to 6] difference in %V).

Conclusions: Ergoreflex activity contributes to hyperventilation, but only in CHF patients with persistent symptoms, and is closely related to the MAGGIC risk score. Ergoreflex activity was not present in patients with IHD or stable CHF, suggesting other reasons for the increased ventilatory drive in those patients.

Keywords: Ergoreflex; MAGGIC risk score; healthy subjects; heart failure; ischemic heart disease; ventilation.