Routine ECG and orthostatic vital signs are recommended for patients with anorexia nervosa, with inpatient telemetry reserved for severe arrhythmias or syncope.
It is reasonable to obtain routine electrocardiography and measurements of orthostatic vital signs in patients presenting with anorexia nervosa. Echocardiography is generally not indicated unless prompted by clinical signs of disease. Admission to an inpatient unit with telemetry monitoring is recommended for patients with severe sinus bradycardia or junction rhythm, marked prolongation of the corrected QT interval, or syncope.
Sachs et al. (2015) studied this question.