Low-level carotid baroreceptor stimulation suppresses ventricular arrhythmias during acute ischemia

PLoS One. 2014 Oct 6;9(10):e109313. doi: 10.1371/journal.pone.0109313. eCollection 2014.

Abstract

Background: The autonomic imbalance during acute ischemia is involved in the occurrence of life-threatening arrhythmias.

Objective: To investigate the effect of autonomic nervous system (ANS) modulation by low-level carotid baroreceptor stimulation (LL-CBS) on ventricular ischemia arrhythmias.

Methods: Anesthetized dogs were received either sham treatment (SHAM group, n = 10) or LL-CBS treatment (LL-CBS group, n = 10). The voltage lowering the blood pressure was used as the threshold for setting LL-CBS at 80% below the threshold. Treatment started 1 hour before left anterior descending coronary (LAD) occlusion, and continued until the end of experience. Ventricular effective refractory periods (ERP), monophasic action potential duration at 90% (APD90), ventricular arrhythmias, indices of heart rate variability, left stellate ganglion nerve activity (LSGNA) and infarct sizes were measured and analyzed.

Results: Ventricular ischemia resulted in an acute reduction of blood pressure, which was not significantly affected by LL-CBS. After 1 hour of LL-CBS, there was a progressive and significant increase in ERP, increase in APD90, and decrease in LSGNA vs the SHAM group (all P<0.05). LL-CBS apparently reduced premature ventricular contractions (PVC, 264±165 in the SHAM group vs 60±37 in the LL-CBS group; P<0.01) during LAD occlusion. Number of episodes of ventricular fibrillation (VF) was 8 in the Control group versus 3 in the LL-CBS group (80% versus 30%, P<0.05). LL-CBS obviously increased high frequency (HF) component (P<0.05) and decreased low frequency/high frequency ratio (P<0.05) compared with the SHAM group. Ischemic size was not affected by LL-CBS between the two groups.

Conclusions: LL-CBS reduced the occurrences of ventricular arrhythmias during acute ischemia without affecting blood pressure. The procedure was associated with changes of electrophysiological characteristics, nerve activity and heart rate variability. Therefore, LL-CBS may protect from ventricular arrhythmias during acute ischemic events by modulating ANS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials
  • Acute Disease
  • Animals
  • Arrhythmias, Cardiac / complications*
  • Carotid Arteries / metabolism*
  • Coronary Occlusion / complications
  • Dogs
  • Electric Stimulation*
  • Evoked Potentials
  • Heart Ventricles / physiopathology
  • Hemodynamics
  • Male
  • Myocardial Ischemia / complications*
  • Myocardial Ischemia / metabolism
  • Myocardial Ischemia / physiopathology
  • Myocardial Ischemia / therapy*
  • Pressoreceptors / metabolism*
  • Stellate Ganglion / physiopathology

Grants and funding

This work was supported by the National Natural Science Foundation of China (81270339 and 81300182), the Natural Science Foundation of Hubei Province (2013CFB302). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.