Cardiovascular diseases (CVDs) are the leading cause of death globally. Decrease in female sex hormones during menopause increases the risk of cardiovascular disease, mainly ischemic heart disease (IHD). Quercetin, a flavonoid, has beneficial properties in CVDs due to its antioxidant, anti-inflammatory, and anti-apoptotic effects. The aim of this study was to investigate the effects of quercetin on susceptibility to cardiac reperfusion arrhythmias and mitochondrial function in ovariectomized rats (OVX). Three-month-old Wistar female rats were randomly assigned to the following experimental groups: SHAM-operated, vehicle-treated (DMSO 10% + PBS, 1 mL kg