Background: Anabolic androgenic steroids (AAS) are sometimes used by power athletes to improve performance by increasing muscle mass and strength. Recent bioptical data have shown that in athletes under the pharmacological effects of AAS, a focal increase in myocardial collagen content might occur as a repair mechanism against myocardial damage. Objective: To investigate the potential underlying left ventricular myocardial dysfunction after chronic misuse of AAS in athletes by use of Doppler myocardial imaging (DMI) and strain rate imaging (SRI). Methods: Standard Doppler echocardiography, DMI, SRI and ECG treadmill test were undertaken by 45 bodybuilders, including 20 athletes misusing AAS for at least 5 years (users), by 25 anabolic-free bodybuilders (non-users) and by 25 age-matched healthy sedentary controls, all men. The mean (SD) number of weeks of AAS use per year was 31.3 (6.4) in users, compared with 8.9 (3.8) years in non-users, and the mean weekly dosage of AAS was 525.4 (90.7) mg. Results: The groups were matched for age. Systolic blood pressure was higher in athletes (145 (9) vs 130 (5) mm Hg) than in controls. Left ventricular mass index did not significantly differ between the two groups of athletes. In particular, both users and non-users showed increased wall thickness and relative wall thickness compared with controls, whereas left ventricular ejection fraction, left ventricular end-diastolic diameter and transmitral Doppler indexes were comparable for the three groups. Colour DMI analysis showed significantly lower myocardial early: myocardial atrial diastolic wave ratios in users at the level of the basal interventricular septum (IVS) and left ventricular lateral wall (p,0.01), in comparison with both non-users and controls. In addition, in users, peak systolic left ventricular strain rate and strain were both reduced in the middle IVS (both p,0.001) and in the left ventricular lateral free wall (both p,0.01). By stepwise forward multivariate analyses, the sum of the left ventricular wall thickness (b coefficient = 20.32, p,0.01), the number of weeks of AAS use per year (b = 20.42, p,0.001) and the weekly dosage of AAS (b = 20.48, p,0.001) were the only independent determinants of middle IVS strain rate. In addition, impaired left ventricular strain in users was associated with a reduced performance during physical effort (p,0.001). Conclusions: Several years after chronic misuse of AAS, power athletes show a subclinical impairment of both systolic and diastolic myocardial function, strongly associated with mean dosage and duration of AAS use. The combined use of DMI and SRI may therefore be useful for the early identification of patients with more diffused cardiac involvement, and eventually for investigation of the reversibility of such myocardial effects after discontinuation of the drug.