Remote-controlled vagal nerve stimulation attenuates ventricular arrhythmias and prevents heart failure progression in a rat model of acute myocardial infarction.

BACKGROUND

Myocardial infarction (MI) often leads to complications like ventricular arrhythmias and heart failure, driven by autonomic nervous system imbalance. This study evaluates the effectiveness of a novel remote-controlled vagal nerve stimulation (VNS) device, featuring adjustable stimulation parameters post-implantation, specifically focusing on its potential to inhibit ventricular arrhythmias and prevent the progression of heart failure in a rat model of acute MI.

METHODS

Male Sprague-Dawley rats were randomized, and MI was induced by ligation of the left anterior descending artery. Seven days post-MI, rats were divided into three groups: the MI + VNS group (n = 15), the MI + control group (n = 15), and a sham-operated group (n = 12). In the MI + VNS group, a VNS device was implanted with initial stimulation settings of 0.2 mA, 0.2 ms pulse width, and 20 Hz frequency. During follow-up, stimulation parameters were adjusted to maintain a 5-20 % reduction in heart rate from baseline. Cardiac function, arrhythmia inducibility, and myocardial fibrosis were assessed four weeks after VNS implantation.

RESULTS

Remote-controlled VNS significantly improved left ventricular ejection fraction and fractional shortening compared to the MI + control group (all P < 0.001). The left ventricular end-systolic diameter was also significantly reduced (P = 0.003). Additionally, VNS-treated rats exhibited a lower incidence and duration of ventricular arrhythmias (P = 0.003) and a reduction in myocardial fibrosis (P < 0.001). Plasma levels of B-type natriuretic peptide and noradrenaline were also significantly lower in the VNS group compared to controls (all P < 0.001).

CONCLUSIONS

These findings suggest that remote-controlled VNS offers a novel and dynamic approach to treating MI-related complications. By allowing for adaptive stimulation in response to real-time physiological changes, remote-controlled VNS may represent a valuable strategy for reducing the risk of heart failure and arrhythmias post-MI.