SYNCOPE, also known as fainting, is a brief, self-limited loss of consciousness with the inability to maintain postural tone that is followed by rapid recovery.

It is very common and is said to affect approximately half of the population at least once in a person’s lifetime and its occurrence increases with age.

Syncope has myriad causes. The end result, however, is a reduction of blood flow to the reticular activating system in the brain that controls wakefulness or global hypoperfusion, so that it is starved of oxygen and glucose, which is mostly caused by hypotension or low blood pressure. This hypotension can be due to the heart failing to pump enough blood to the brain; the blood vessels not having enough tone to maintain the blood pressure; or not enough blood or fluid in the vessels; or a combination of the three. Once the blood flow to the brain is restored, usually by the patient slumping to the floor, a chair or bed, then the person recovers immediately.

Syncope should be differentiated from other mimics such as seizures, coma, shock, concussion or head trauma, and other causes of altered consciousness.

Syncope can result from non-life-threatening causes such as emotional upset; seeing blood; dehydration; drugs; standing upright for long periods or orthostasis, coughing, and emptying the bladder or bowel.

It can also result from life-threatening causes such as problems with the electrical activity of the heart, which include sinus arrest/pause, heart blocks, and ventricular arrhythmias, or structural problems affecting the heart and blood vessels. Sometimes the cause remains unknown.

Syncope can result in physical trauma and if recurrent can affect one’s quality of life.

MANAGING SYNCOPE

After collapsing, the patient should be made to lie flat to assist blood flow to return to the brain.

Patients who have fainted should see a doctor. They would be asked to recall the symptoms and signs that occurred before they fainted, what they were doing, the position they were in, the events that occurred during and after (from witnesses) and if they are on any medication or have any pre-existing medical or familial condition.

People may report feeling light-headed, dizzy or weak prior to losing awareness. Symptoms of concern include: chest pain, collapsing during activity, abnormal heart beat, shortness of breath, severe headache, lower back pain or neurological deficits such as problem speaking, seeing, weakness in face, or limbs.

A complete examination would then be performed, including vital signs analysis and glucose check, along with some simple bedside manoeuvres. Blood tests; electrocardiogram (ECG), carotid artery studies, and other imaging studies would then be dictated based on the suspected cause of the syncope. Treatment would then be tailored according to the cause, and preventative measures would then be advised.

Managing syncope due to orthostasis or neurally mediated syncope would focus on educating the patient not to move from a seated to a standing position too quickly, or avoid standing for long hours without moving to assist blood flow; reducing drugs that will lower blood pressure and heart rate; encourage hydration; avoid tight collars or prolonged periods of low blood sugar.

Syncope due to cardiac or neurologic causes is usually sinister and requires admission to hospital for complete work up and treatment by a cardiologist, cardiothoracic surgeon or neurologist, accordingly.

Dr Romayne Edwards is a consultant emergency physician at the University Hospital of the West Indies and an associate lecturer at the University of the West Indies.