Chronic vagus nerve stimulation improves autonomic control and attenuates systemic inflammation and heart failure progression in a canine high-rate pacing model.
BACKGROUND
Autonomic dysfunction, characterized by sympathetic activation and vagal withdrawal, contributes to the progression of heart failure (HF). Although the therapeutic benefits of sympathetic inhibition with beta-blockers in HF are clear, the role of increased vagal tone in this setting has been less studied. We have investigated the impact of enhancing vagal tone (achieved through chronic cervical vagus nerve stimulation, [VNS]) on HF development in a canine high-rate ventricular pacing model.


RESULTS
Fifteen dogs were randomized into control (n=7) and VNS (n=8) groups. All dogs underwent 8 weeks of high-rate ventricular pacing (at 220 bpm for the first 4 weeks to develop HF and another 4 weeks at 180 bpm to maintain HF). Concomitant VNS, at an intensity reducing sinus rate approximately 20 bpm, was delivered together with the ventricular pacing in the VNS group. At 4 and 8 weeks of ventricular pacing, both left ventricular end-diastolic and -systolic volumes were lower and left ventricular ejection fraction was higher in the VNS group than in the control group. Heart rate variability and baroreflex sensitivity improved in the VNS dogs. Rises in plasma norepinephrine, angiotensin II, and C-reactive protein levels, ordinarily expected in this model, were markedly attenuated with VNS treatment.


CONCLUSIONS
Chronic VNS improves cardiac autonomic control and significantly attenuates HF development in the canine high-rate ventricular pacing model. The therapeutic benefit of VNS is associated with pronounced anti-inflammatory effects. VNS is a novel and potentially useful therapy for treating HF.
Zhang
Youhua
Y
Department of Molecular Cardiology and Cardiovascular Medicine, Cleveland Clinic, USA. zhangy2@ccf.org
Popovic
Zoran B
ZB
Bibevski
Steve
S
Fakhry
Itaf
I
Sica
Domenic A
DA
Van Wagoner
David R
DR
Mazgalev
Todor N
TN
D000804:Angiotensin II / Q000097:blood; D000818:Animals; D017704:Baroreflex; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure; D002097:C-Reactive Protein / Q000378:metabolism; D002304:Cardiac Pacing, Artificial; D004195:Disease Models, Animal; D004285:Dogs; D005260:Female; D006333:Heart Failure / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D006339:Heart Rate; D008297:Male; D009638:Norepinephrine / Q000097:blood; D013318:Stroke Volume; D013564:Sympathetic Nervous System / Q000378:metabolism / Q000503:physiopathology*; D018746:Systemic Inflammatory Response Syndrome / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D013997:Time Factors; D014630:Vagus Nerve / Q000503:physiopathology*; D055536:Vagus Nerve Stimulation / Q000009:adverse effects; D016277:Ventricular Function, Left
D015415:Biomarkers; D000804:Angiotensin II; D002097:C-Reactive Protein; D009638:Norepinephrine