Abstract 18057: Impact of Elevated Peripheral Chemosensitivity on Spontaneous Baroreflex Function in Chronic Heart Failure Patients with Cardiorenal Anaemia Syndrome
Objective Cardiorenal anaemia syndrome is known to increase mortality and morbidity in patients with CHF. The role of the sympathetic nervous system and related-reflexes in the pathophysiology remains unknown.
Design and Methods The prospective study was conducted at the Intensive Cardiac Care Unit, Rangueil University Hospital, Toulouse, France. We studied 15 patients with CRA syndrome (age: 66.5 ± 3.1 years; mean BMI: 24.12 ± 0.9 kg/m2) and 15 control patients with CHF alone matched for age, gender distribution, type of cardiomyopathy, left ventricular ejection fraction (LVEF) and BMI. We compared sympathetic nerve activity (MSNA), sympathetic baroreflex function (assessed by the slope of the relationship between muscle sympathetic nerve activity (MSNA) and diastolic blood pressure) and its modulation by peripheral chemoreflex, in both groups.
Results Baseline MSNA was significantly elevated in CHF patients with CRA syndrome compared with patients with CHF alone (83.1 ± 4.6 versus 64.9 ± 2.9 bursts/100 heart beats; P<0.01) and sympathetic baroreflex function impaired (2.69 ± 0.44 versus 5.25 ± 0.60 %/mmHg; P<0.01). In comparaison with control, chemoreflex deactivation with administration of 100% oxygen led to a significant decrease in muscle sympathetic nerve activity and an increase in arterial baroreflex sensitivity in patients with CRA syndrome.
Conclusion CRA syndrome is associated with elevated sympathetic activity mediated by both baroreflex impairment and tonic activation of peripheral chemoreflex. The latter, through direct interaction with sympathetic baroreflex function subsequently contributes to further activation of the SNS tone. Altogether, mechanisms described in this study could partly explain how CRAS contributes to the progression of CHF and increases morbidity and mortality in these patients.
- © 2011 by American Heart Association, Inc.