At least one-third of all deaths in patients with anorexia nervosa are estimated to be due to cardiac causes, mainly sudden death14,15,18 Cardiovascular complications are common and they have been reported in up to 80% of patients with anorexia nervosa, mainly in the form of bradycardia, hypotension, arrhythmias, repolarization abnormalities, and sudden death by up to 10% of the cases with these types of cardiovascular disturbances14–16,19–21 Food restriction can lead to increased vagal tone, bradycardia, orthostatic hypotension, syncope, arrhythmias, congestive heart failure, and sudden death22 Duration of the QT interval of the electrocardiogram is a function of the heart rate and a prolonged QT interval is a biomarker for ventricular tachyarrhythmia and a risk factor for sudden death15,16,79 The measurement of QT interval has a poor predictive value for the recognition of patients who are at particular risk of sudden death. A measured QT interval of >600 milliseconds is associated with a significant risk of sudden death, but few patients usually have such long QT intervals24 In refeeding syndrome, congestive heart failure results from decreased ventricular mass and myofibrillar atrophy, causing decreased stroke volume and reduced capacity of the cardiovascular system4 Some cases of myocardial infarction have been described in eating disorder patients. This complication increases the risk of sudden death among those patients35,36 Another mechanism of cardiovascular mortality and sudden death among eating disorder patients is the alteration in sympathovagal balance39
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