OBJECTIVE--To identify the characteristics of cardiac involvement in the self-induced starvation phase of anorexia nervosa. METHODS--Doppler echocardiographic indices of left ventricular geometry, function, and filling were examined in 21 white women (mean (SD) 22 (5) years) with anorexia nervosa according to the DSMIII (Diagnostic and Statistical Manual of Mental Disorders) criteria, 19 women (23 (2) years) of normal weight, and 22 constitutionally thin women (21 (4) years) with body mass index < 20. RESULTS--13 patients (62%) had abnormalities of mitral valve motion compared with one normal weight woman and two thin women (p < 0.001) v both control groups). Left ventricular chamber dimension and mass were significantly less in women with anorexia nervosa than in either the women of normal weight or the thin women, even after standardisation for body size or after controlling for blood pressure. There were no substantial changes in left ventricular shape. Midwall shortening as a percentage of the values predicted from end systolic stress was significantly lower in the starving patients than in women of normal weight: when endocardial shortening was used as the index this difference was overestimated. The cardiac index was also significantly reduced in anorexia nervosa because of a low stroke index and heart rate. The total peripheral resistance was significantly higher in starving patients than in both control groups. The left atrial dimension was significantly smaller in anorexia than in the women of normal weight and the thin women, independently of body size. The transmitral flow velocity E/A ratio was significantly higher in anorexia than in both the control groups because of the reduction of peak velocity A. When data from all three groups were pooled the flow velocity E/A ratio was inversely related to left atrial dimension (r = -0.43, p < 0.0001) and cardiac output (r = -0.64, p < 0.0001) independently of body size. CONCLUSIONS--Anorexia nervosa caused demonstrable abnormalities of mitral valve motion and reduced left ventricular mass and filling associated with systolic dysfunction.