Carotid baroreceptor stimulation prevents arrhythmias induced by acute myocardial infarction through autonomic...

Area of Science:

• Cardiovascular Physiology
• Autonomic Nervous System Regulation
• Cardiac Electrophysiology

Background:

• Electrical carotid baroreceptor stimulation (CBS) shows promise for hypertension and heart failure by modulating the autonomic nervous system.
• The specific effects of CBS on cardiac arrhythmias, particularly after acute myocardial infarction (AMI), are not well understood.

Purpose of the Study:

• To investigate the impact of CBS on ventricular electrophysiological properties.
• To evaluate the efficacy of CBS in mitigating arrhythmias following AMI in a canine model.

Main Methods:

• Anesthetized open-chest dogs underwent a 1-hour left anterior descending coronary occlusion to model AMI.
• Dogs were randomized to receive either sham treatment (Control) or CBS, initiated 1 hour prior to AMI induction.
• Ventricular electrophysiological parameters, including effective refractory period and action potential duration restitution, were measured.
• The incidence of premature ventricular contractions, ventricular tachycardia, and ventricular fibrillation was quantified during AMI.

Main Results:

• CBS significantly prolonged the ventricular effective refractory period and reduced the action potential duration restitution slope before AMI.
• The incidence of premature ventricular contractions was significantly lower in the CBS group compared to the Control group during AMI.
• Episodes of ventricular tachycardia/ventricular fibrillation were markedly reduced in dogs receiving CBS.
• CBS attenuated the changes in the low-frequency/high-frequency ratio of heart rate variability during AMI, without affecting ischemic size.

Conclusions:

• Electrical carotid baroreceptor stimulation demonstrates a protective effect against ventricular arrhythmias induced by acute myocardial infarction.
• CBS favorably modulates autonomic tone and ventricular electrophysiology, contributing to its anti-arrhythmic benefits in the context of AMI.
• These findings suggest a potential therapeutic role for CBS in managing cardiac arrhythmias associated with myocardial infarction.