Syncope is a medical term used to describe 'fainting' or temporary loss of consciousness. It most often occurs when blood pressure is too low (hypotension), and the heart doesn't pump enough oxygen to the brain. It can be benign or a symptom of an underlying medical condition.
PATHOPHYSIOLOGY
It occurs as a result of brain hypoxia (i.e., when there is little or no oxygen in the brain) and this can be traced down to reduction in systemic blood pressure that causes a decrease in cerebral circulation leading to loss of consciousness.
CAUSES
It is a symptom that can be due to several causes, ranging from benign to life-threatening factors, such as overheating, dehydration, heavy sweating, exhaustion, or the pooling of blood in the legs due to sudden changes in body position, can trigger syncope.
EPIDEMIOLOGY
It is a condition which is common and affects about 3% of men and 3.5% of women at some point in life. Syncope is more common as you get older and affects up to 6% of people over age 75. The condition can occur at any age and happens in people with and without other medical problems.
TYPES OF SYNCOPE
There are different types of syncope, but it is estimated that about 40% of syncope cases have an unknown cause. They include:
Cardiac Syncope:
If one experiences frequent fainting and it is not as a result of dehydration or sudden posture change, then the patient needs to be tested for a heart condition. Cardiac syncope can be caused by aortic dissection, aortic valve stenosis, arrhythmia etc.
Its features include chest pain or heart palpitations before fainting, fainting while lying down.
It's risk factors include:
family history of heart diseases
male gender
affects elderly people of 60 years and above
heart disease
Reflex Syncope:
It is also called neurally mediated and is known to be the most common type of syncope. When this type of syncope takes place, it causes the heart to slow down accompanied by a drop-in blood pressure leading to a flow of blood to the brain.
There are 3 kinds of reflex syncope:
Vasovagal: This happens when the body overreacts to a trigger such as stress, intense pain.
Situational: This type of syncope happens when certain actions are done e.g. swallowing, coughing etc.
Carotid sinus: It happens when there is pressure on the carotid artery.
Features of reflex syncope include blurry vision, nausea, lightheadedness.
Orthostatic Syncope:
It happens due to a drop in blood pressure when one stands up. When a person stands up the brain helps to stabilize the blood pressure, but with orthostatic syncope, this does not take place thereby causing syncope. Factors which could lead to this include:
Alcohol
Underlying disease conditions such as diabetes
Medications e.g. antihypertensives
Anaemia
Dehydration
Cerebrovascular Syncope:
It occurs when a problem arises with the blood vessels in and around the brain which could prevent blood from getting to the brain.
Factors which could cause this type of fainting include:
Injury from cerebrovascular diseases such as stroke, carotid stenosis etc.
Basilar artery diseases
Some symptoms associated with cerebrovascular syncope include:
Trouble hearing
Confusion
Uncoordinated movement etc.
It's risk factors include;
Older age
Cardiovascular diseases e.g. high cholesterol, high blood pressure
Cerebrovascular diseases
DIAGNOSIS
Physical exam
Diagnostic tests
Laboratory test e.g. diabetes, anaemia etc.
Mass refractive index
Carotid sinus massage
-Tilt- table test
Kidney function test
Electrocardiogram
SYMPTOMS
These symptoms usually happen before syncope occurs, which include;
slurred speech
weak pulse
changes in body temperature
pale skin
visual disturbances such as blurry vision, dilated pupils etc.
vertigo
headache
body weakness
numbness
It is important to know that if you should experience any warning signs and symptoms like faint it is best to pause on whatever you are doing and sit or lie down for some time. Try to lie flat on your back and raise your legs higher than your head. The reason for doing this is to support back the flow of blood to the brain which if done on time could help prevent a syncopal episode.
TREATMENT
Pharmacological Action:
Use of corticosteroids e.g. Fludrocortisone
Midodrine
Use of anticholinergics such as hyoscyamine
Use of ephedrine
Non - Pharmacological Action
If you are feeling faint; Lie down on your back with your head low and legs raised. (This will help with blood flow to the brain) but if you cannot lie down, sit down.
In situations where you cannot lie down, sit down, and put your head between your knees to increase the flow of blood to the brain.
Don't get up too quickly, as the episode might occur again.
In cases of being around people who have fainted;
Check for injuries and if they are still breathing
If they are uninjured, help position them as explained earlier using either way. But in a situation where the patient is not breathing or hasn't regained consciousness, call for medical help immediately.
PREVENTION
To prevent recurrent episodes of syncope can be achieved through educating the patient on this condition and on the treatment. This will help patients to know what could trigger their episode.
Drink plenty of fluids
Avoid clothing with tight collars
Don't skip meals
Understand the factors which could trigger a syncope episode
Take your time when standing up
REFERENCE
American Heart Association. Syncope (Fainting).
Cleveland clinic. (2019). Syncope: Symptoms, Causes, Treatments.
topics/arrhythmia/symptoms-diagnosis
Seladi-Schulman, J. (Ph.d) Medically reviewed by Heidi Moawad,M.D( October 9th,2019) . Healthline.
Corey, W; Medically reviwed by Suzanne Falck, M.D., FACP, updated on January 24,2017. Healthline.
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