Underweight and loss of a...

A 12-year-old girl was referred to our clinic with a diagnosis of anorexia. She refused to eat during the last months and was underweight (weight 31 kg, height 145 cm, body mass index (BMI) =14.7 kg/cm2). She had no palpitation, syncope or other cardiac complaints. On admission, laboratory investigations revealed a normal complete blood count, electrolytes, sedimentation rate, liver and kidney function tests, amylase, cholesterol and thyroid-stimulating hormone. The follicle-stimulating hormone, luteinizing hormone and oestradiol were in normal levels for this age. To find the cause of underweight, gastro-duodeno-oesophagoscopy and brain computer tomography (CT)-scan were performed. No abnormalities were found. 

Examination

Twelve-lead resting electrocardiography revealed sinus rhythm with slight prolongation of PR interval (The echocardiography revealed a normal structure of the heart. The 40-h ambulatory electrocardiography (ECG) monitoring showed more than 70 episodes of 2:1 AV block and high degree (up to 7:1) of AV block with no escape rhythm [ventricular pauses up to 6 s].