Objective To investigate the changes in cardiac electrophysiology and cardiac function in rats afterlimb amputation and their relationships with the endothelial nitric oxide synthase/ nitric oxide ( eNOS/ NO) pathway.Methods Seventy-two healthy 8-week old male Wistar rats were divided into the normal group (anesthesia only),amputation control, amputation 0. 25 h, amputation 0. 5 h, amputation 0. 75 h, and amputation 1. 5 h groups (n=12 ratsper group). The left hind limb trauma model was established by amputation surgery. Changes in heart rate, QT interval,and PR interval were detected by electrocardiogram; the left ventricular ejection fraction (LVEF) and left ventricular shortaxis shortening rate (LVFS) were measured by echocardiography; the left ventricular systolic pressure (LVSP), thehighest rate of increase of left ventricular pressure (+dp/ dt max), and the highest rate of decrease of left ventricularpressure (-dp/ dt max) were measured by right carotid artery intubation; the level of malondialdehyde (MDA) in themyocardium was measured with thiobarbituric acid; the level of superoxide dismutase (SOD) was detected by pyrogallolcolorimetry; Green’s method was used to detect the nitric oxide (NO) levels; levels of myeloperoxidase (MPO), tumornecrosis factor-ɑ (TNF-α), and interleukin-6 (IL-6) were detected by enzyme-linked immunosorbent assay; hematoxylinand eosin staining was used to observe the histopathological changes in the myocardium; myocardial cell apoptosis wasobserved by TUNEL staining; and the expression of eNOS, Bcl-2, and Bcl-2-related X protein (Bax) in the myocardiumwas detected by western blotting. Results Compared with the normal group, the following changes were observed 0. 5 hand 0. 75 h after amputation: the heart rate increased, the QT interval decreased, LVSP, +dp/ dmax, -dp/ dmax, LVEF,and LVFS decreased, MPO, MDA, SOD, TNF-α, and IL-6 increased, and the myocardial cells were loosely arranged,necrotic, and accompanied with a large amount of inflammatory cell infiltration. Moreover, at these same time points, thefollowing significant changes were observed in a time-dependent manner ( P < 0. 05): an increased apoptotic index ofcardiomyocytes, decreased expression of Bcl-2 protein in the myocardium, increased expression of Bax protein, anddecreased NO level and eNOS protein expression. Compared with 0. 75 h after amputation group, the heart rate decreased at0. 5 h after amputation, the QT interval and PR interval increased, LVSP, +dp/ dmax, -dp/ dmax, LVEF, and LVFSincreased, MPO, MDA, SOD, TNF-α, and IL-6 decreased, and the degree of myocardial pathological injury wasalleviated. Moreover, significant differences were seen as following: a decreased apoptotic index of cardiomyocytes,increased Bcl-2 and eNOS protein expression, increased NO levels, and decreased Bax protein expression ( P <0. 05).Conclusions Amputation trauma causes ischemic electrocardiogram changes, cardiac function damage, excessiveoxidative stress, and inflammatory damages in rats. The underlying mechanism may be related to inhibition of the eNOS/ NO pathway.