Cardiac complications include structural and functional changes to the heart. Some of these cardiovascular changes are mild and are reversible with treatment, while others may be life-threatening. Cardiac complications can include arrhythmias, abnormally slow heart beat, low blood pressure, decreased size of the heart muscle, reduced heart volume, mitral valve prolapse, myocardial fibrosis, and pericardial effusion.Abnormalities in conduction and repolarization of the heart that can result from anorexia nervosa include QT prolongation, increased QT dispersion, conduction delays,  and junctional escape rhythms. Electrolyte abnormalities, particularly hypokalemia and hypomagnesemia, can cause anomalies in the electrical activity of the heart, and result in life-threatening arrhythmias. Hypokalemia most commonly results in patients with anorexia when restricting is accompanied by purging (induced vomiting or laxative use). Hypotension (low blood pressure) is common, and symptoms include fatigue and weakness. Orthostatic hypotension, a marked decrease in blood pressure when standing from a supine position, may also occur. Symptoms include lightheadedness upon standing, weakness, and cognitive impairment, and may result in fainting or near-fainting. Orthostasis in anorexia nervosa indicates worsening cardiac function and may indicate a need for hospitalization. Hypotension and orthostasis generally resolve upon recovery to a normal weight. The weight loss in anorexia nervosa also causes atrophy of cardiac muscle. This leads to decreased ability to pump blood, a reduction in the ability to sustain exercise, a diminished ability to increase blood pressure in response to exercise, and a subjective feeling of fatigue.Some individuals may also have a decrease in cardiac contractility.
A Jefferson fracture is a bone fracture of the anterior and posterior arches of the C1 vertebra, though it may also appear as a three- or two-part fracture. The fracture may result from an axial load on the back of the head or hyperextension of the neck (e.g. caused by diving), causing a posterior break, and may be accompanied by a break in other parts of the cervical spine.It is named after the British neurologist and neurosurgeon Sir Geoffrey Jefferson, who reported four cases of the fracture in 1920 in addition to reviewing cases that had been reported previously. Signs and symptoms
Individuals with Jefferson fractures usually experience pain in the upper neck but no neurological signs. The fracture may also cause damage to the arteries in the neck, resulting in lateral medullary syndrome, Horners syndrome, ataxia, and the inability to sense pain or temperature.In rare cases, congenital abnormality may cause the same symptoms as a Jefferson fracture. Cause
Jefferson fracture is often caused by an impact or load on the back of the head, and are frequently associated with diving into shallow water, impact against the roof of a vehicle and falls, and in children may occur due to falls from playground equipment. Less frequently, strong rotation of the head may also result in Jefferson fractures.Jefferson fractures are extremely rare in children, but recovery is usually complete without surgery. Diagnosis
Treatment
The use of surgery to treat a Jefferson fracture is somewhat controversial.