Background: Anorexia nervosa (AN) is often associated with cardiac changes, such as thinning of the left ventricle (LV), reduction of LV mass, abnormalities of mitral valve function and systolic dysfunction. Some authors have reported QT interval prolongation and sudden death in these patients.
Methods: We studied 23 adolescent females, aged 14.7 +/- 2 years (mean +/- SD), with AN. Serum electrolytes, proteins and albumin were measured in all patients. Electrocardiogram, Doppler-echocardiogram and chest X-rays were also performed on the same day. Eighteen patients were also examined via indirect calorimetry (difference from basal metabolic rate) and 21 underwent dosage of thyroid hormones.
Results: The patients, who were of normal height (159 +/- 7.4 cm), were underweight (36 +/- 4.8 kg) and had a body mass index (BMI) of less than 19 (14.2 +/- 1.3). Serum electrolytes, proteins, albumin and chest X-rays were substantially normal in all patients; 74% of them showed reduction of FT3. The calorimetry was reduced (-27.1 +/- 10.6%) with the exception of one patient. Resting heart rate was 58 +/- 12 bpm. We found normal values for PR, QRS, QT (0.41 +/- 0.03 s1/2) and QTc intervals (0.40 +/- 0.03 s1/2) and QT dispersion (40.9 +/- 14.1 ms). Echocardiography showed a reduction in the dimensions of the interventricular septum (52% of patients), LV free wall (61%), left atrium (31%) and LV mass (61%). Fractional shortening was normal in all but one patient. In 61% of cases, there was mild or moderate pericardial effusion that was clinically silent and inversely related to BMI (r = -0.38, p 0.08, ns), to calorimetry (r = -0.56, p < 0.0055), to FT3 (r = -0.53, p < 0.05) and to sodium concentration (r = -0.43, p 0.04).
Conclusions: Teen-agers with AN often show a reduction in LV thickness and mass, as well as clinically silent pericardial effusion that is inversely related to BMI, calorimetry, FT3 and sodium serum concentrations. We did not find any prolongation of QTc interval or of QT dispersion.