Investigation of the effect of 8 weeks of high-intensity interval training and berberine supplementation on some echocardiography and electrocardiogram indices following myocardial ischemia-reperfusion in rats

Abstract

Background: Myocardial ischemia leads to left ventricular (LV) dysfunction and cardiac arrhythmia. The present research was conducted with the aim to explore echocardiography changes and electrocardiogram parameters of the hearts of rats with ischemia-reperfusion injury (IRI).

Methods: The study subjects included 50 male Wistar rats) 8-10 weeks), which were divided into 5 groups (1: trained, 2: supplemented, 3: combined (training and supplementation), 4: sham, and 5: control). High-intensity interval training ý(HIIT) was performed for 8 weeks, 5 sessions per week. Rats belonging to groups 2 and 3 received 10 mg/kg berberine. Finally, after 48 hours, electrocardiogram and echocardiography were performed on all rats. Moreover, myocardial ischemia was performed by descending coronary artery ligation for 30 minutes.

Results: There were significant differences between the 5 groups in terms of the volumes and dimensions of LV end-systolic dimension (LVSD), LV end-diastolic dimension (LVDD)ý, fractional shortening cardiac output, ejection fraction (EF), stroke volume (SV), ventricular tachycardia (VT), and ventricular ectopic beats (VEBs) episodes, duration of VTs, and ECG parameters (P ≤ 0.05).

Conclusion: Berberine supplementation and HIIT, as preconditioning agents, can possibly prevent the elevation of EF and fractional shortening, the reduction of cardiac output and SV, and arrhythmia improvement after myocardial IRI. Finally, these changes result in increased LV function and decreased mortality in rats with myocardial IRI.

Keywords: Berberine; Echocardiography; Electrocardiography; High-intensity interval training; Infarction.

Figure 1

Myocardial ischemia-reperfusion in the studied rats on a bed equipped with a thermal pad in order to maintain the body temperature of the subject, a ventilator connection to supply oxygen, and a power lab device to evaluate electrocardiogram changes

Figure 2

Stroke volume changes in different groups: (A) *Sign of difference in comparison with control group (P ≤ 0.05); cardiac index changes in different groups; (B) *Sign of difference in comparison with control group (P < 0.05)

Figure 3

Ventricular arrhythmias during ischemia: (A) the total number of ventricular tachycardia and ventricular ectopic beats during 30‐min ischemia in different groups; and (B) duration (s) of VT during 30‐min ischemia in different groups Data are presented as mean ± SD. *Sign of difference in comparison with control group (P ≤ 0.05)