Anabolic androgenic steroids (AAS) are used by some athletes to enhance performance despite the health risk they may pose in some persons. This work was carried out to evaluate the possible structural and functional alterations in the heart using two-dimensional, M-mode, tissue Doppler imaging (TDI) and strain rate imaging (SRI) in athletes using supraphysiological doses of AAS. Additionally, the histological and ultrastructural changes in cardiac muscles of adult albino rats after injection of sustanon, as an example of AAS, were studied. Fifteen male bodybuilders using anabolic steroids constituted group 1, five male bodybuilders who are not using anabolic steroids constituted group 2, and five nonathletic males constituted negative control group (group 3). They were investigated by two-dimensional, M-mode, TDI and SRI. This study was performed on 30 adult albino rats. They were divided into two groups. Group I (Control group) (10) was subdivided into negative control, subgroup 1a (5), and subgroup 1b (5), which received 0.8 ml olive oil intramuscular once a week for 8 weeks. Group II (Experimental group) (20) received sustanon 10 mg/kg intramuscularly once a week for 8 weeks. The heart specimens were prepared for light microscopy and transmission electron microscopy. Echocardiographic results showed that bodybuilders who use steroids have smaller left ventricular dimension with thicker walls, impaired diastolic function, as well as higher peak systolic strain rate in steroid-using bodybuilders as compared to the other two groups. Light microscopy examination of cardiac muscle fibers showed focal areas of degeneration with loss of striations and vacuolation in the experimental group. Ultrastructural examination showed disturbance of the banding pattern of the cardiac muscle fiber with disintegration, loss of striations, dehiscent intercalated disc, and interrupted Z-bands. Administration of supraphysiological doses of AAS caused severe deleterious effects in the myocardium both in athletes and in experimental animals. The SRI shows promise in the early detection of systolic dysfunction in those athletes who use steroids.