To assess the effect of duration of morbid obesity on left ventricular (LV) structure and function, we performed echocardiography and cardiac Doppler studies in 50 morbidly obese subjects whose duration of morbid obesity ranged from 5 to 28 years, Longer durations of morbid obesity were associated with higher LV mass, poorer LV diastolic filling; weight loss-induced improvements in these variables were due in part to favorable alterations in LV loading conditions.