Tonic arterial chemoreceptor activity contributes to cardiac, but not renal, sympathetic activation in heart failure (1169.2)

Abstract

In heart failure (HF) cardiac sympathetic nerve activity (CSNA) is increased, which has detrimental effects on the heart. The arterial chemoreceptor activation plays an important role in stimulating renal SNA (RSNA) and muscle SNA in HF. We recorded CSNA and renal SNA (RSNA) in conscious normal sheep and in sheep with mild HF induced by rapid ventricular pacing (ejection fraction <40%). Tonic arterial chemoreceptor function was evaluated by deactivating chemoreceptors by supplementing room air with intranasal 100% oxygen (2‐3 L/min) for 20 min. In HF, chemoreceptor deactivation induced by hyperoxia reduced CSNA (90±2 vs. 75±5 bursts/100 beats, P<0.05; 86±5 vs. 66±7 bursts/min, P<0.001; n=10;..