Chronic electroacupuncture of the ST36 point improves baroreflex function and haemodynamic parameters in heart failure rats.

Electroacupuncture (EA) has been used to treat many diseases, including heart failure (HF). This study aimed to evaluate the effects of chronic stimulation in the ST36 acupuncture point on haemodynamic parameters and baroreflex function in rats with HF. Cardiovascular parameters assessed were heart rate (HR), blood pressure (BP), and the reflex cardiovascular response of HR triggered by stimulation of baroreceptors in animals with HF subsequent to acute myocardial infarction (AMI). Male Wistar rats were divided into three groups: Sham Control - animals without HF and without EA; HF Control group - animals with HF and without EA; and HF EA group - animals with HF that received the EA protocol. Six weeks after surgical induction of AMI, the EA protocol (8 weeks, 5 times a week) was performed. The protocol was applied with EA at the ST36 point, frequency of 2 Hz, pulse of 0.3 ms and intensity of 1-3 mA for 30 min. Haemodynamic parameters and baroreceptor function were assessed. There was no difference between groups in the variables HR, systolic blood pressure (SBP) and diastolic blood pressure (DBP), which were evaluated with awake animals (p>0.05). There was an increase in the mean arterial pressure (MAP) in the HF EA group compared to the HF Control group (p<0.05). The maximum gain of the baroreflex heart rate response (Gain) was higher in the HF EA group than the HF Control and Sham Control groups. Chronic EA in the ST36 point increased the MAP and baroreflex sensitivity in rats with HF.