What is Syncope?
Syncope is a condition caused by a brief decrease in blood flow to the brain, which results in temporary unconsciousness and loss of muscle strength, often leading to fainting. It can be associated either with a quick recovery or preceded by symptoms like dizziness, feeling lightheaded, heavy sweating, nausea, and visual difficulties. Sometimes, there might not be any warning signs and a person might suddenly faint.
Syncope is often referred to as fainting, blacking out, or “having a spell.” It accounts for 1 to 3.5% of all trips to the emergency room and 6% of all hospital admissions in the United States. This relatively high rate is due to the varied causes of syncope, which can range from harmless to serious, and the difficulty in diagnosing the root cause of this condition.
What Causes Syncope?
Syncope, also known as fainting, isn’t a disease, but a symptom of another problem. While fainting can be scary to the person fainting and their family, it’s usually not a sign of a serious issue. Fainting often happens due to triggers such as being in a hot or crowded environment, standing for too long, severe pain, or extreme tiredness. These factors can cause the blood vessels to widen (vasodilatation) and the heart rate to slow down (bradycardia), which in turn lead to fainting.
This kind of fainting is most common, accounting for about half of all fainting cases, and it’s commonly called a ‘common faint,’ it can even happen to otherwise healthy people. Some early signs of a ‘common faint’ include blurred vision, sweating, feeling nauseous, feeling dizzy, or feeling weak. These signs are followed by slow heart rate, lower blood pressure, and then fainting. To the people around, the person fainting appears pale. After a few minutes, the person usually wakes up and might feel weak. They don’t lose control over their bladder or bowels and normally don’t have a seizure or feel confused after they wake up.
However, fainting can sometimes be caused by serious issues, specifically related to the heart, like irregular heartbeat (arrhythmias), issues with heart valves, blockages in the heart, or lack of blood flow to the brain. Other causes can include metabolic issues like low blood sugar and low oxygen, as well as stress or panic attacks.
Risk Factors and Frequency for Syncope
Visits to the emergency department due to syncope, or fainting, make up about 1 to 3.5% of all visits in the U.S. It’s more commonly seen in older patients who may have various health issues and take many medications. In these older patients, the cause is often heart-related. But in younger adults, the cause is usually non-heart-related, like vasovagal syncope (a sudden drop in heart rate and blood pressure leading to fainting). There’s no major difference in how often this condition occurs in men and women.
Signs and Symptoms of Syncope
Syncope, also known as fainting, can often be diagnosed in about 50% of patients just through a careful history taking and physical examination. When doctors look into the history of someone who has experienced syncope, they usually focus on how long the fainting spell lasted, what events happened before the fainting and what happened after. They also consider the position the person was in when the fainting episode occurred. If a person was standing, it could point to a vasovagal cause, while if a person was lying down, it could be due to neurocardiac causes. It’s crucial to also know the patient’s medical history and medications. During the physical examination, the doctors might check for any abnormal vital signs, which can hint at underlying health issues like low blood pressure upon standing up, or potential problems with the heart or blood circulation. They will also check for signs of vascular disease, heart failure, or stroke that might be mistaken for syncope.
Testing for Syncope
If you are taken to the emergency room because of fainting, the doctors usually order routine blood tests to check your hemoglobin, electrolyte, and glucose levels. An electrocardiogram (ECG) – a test that records the electrical activity of your heart – is also typically performed on all patients experiencing fainting.
If the doctors think your fainting might be due to a heart problem, further tests can include checking for certain proteins in your blood that indicate heart damage, monitoring your heart’s activity, and performing an echocardiogram – a type of ultrasound of your heart. A Holter monitor, a portable device for continuous monitoring of your heart’s electrical activity, may be recommended if they suspect problems with the electrical signals in your heart.
If the doctors think your fainting might have a brain-related cause, further testing can include a CT (Computerized Tomography) scan of your head, a carotid Doppler ultrasound to check the blood flow in your neck, an MRI (Magnetic Resonance Imaging) of your brain and an MRA (Magnetic Resonance Angiography) which is used to examine blood vessels.
An EEG (Electroencephalography), a test that records electrical activity in your brain, might be performed if the doctors suspect that you might have had a seizure.
Sometimes, a tilt table test can be helpful. This test is used to cause blood pressure and heart rate changes that might lead to fainting, in a controlled setting. Doctors might consider this test if you have had several unexplained fainting episodes, if a “fainting response” to certain triggers is suspected, or to help distinguish between different types of fainting.
While the ECG is generally found to identify the cause of fainting in about 5% of patients, and routine blood work helps diagnose only about 2% of cases, still almost half of the patients might leave the hospital without knowing why they fainted. The good news is that recent data suggests a more focused approach can help identify the causes. For instance, an echocardiogram before a patient goes home can reveal heart valve problems in a patient who fainted and was found to have an abnormal heart sound. Similarly, continuous heart monitoring can help identify abnormal heart rhythms in patients with a history of this problem.
Treatment Options for Syncope
In simpler terms, syncope is fainting or passing out, and it usually happens due to a temporary drop in the amount of blood your brain receives. To successfully treat syncope, it’s important to determine and address the root cause of the issue.
If someone faints, it’s best to make sure they sit or lie down quickly to restore blood flow to their brain. Lifting the legs can also help for those fainting due to sudden drops in blood pressure. It’s essential to keep the person lying down after the fainting episode to prevent them from becoming unsteady. Any injuries that occurred as a result of the fall during fainting need immediate care.
Different types of syncope have unique treatment strategies:
1. Vasovagal syncope: Here, fainting occurs due to a sudden drop in heart rate and blood pressure. The person should avoid situations or triggers that have previously led to fainting. Training to adapt to body position changes and increase salt and fluid intake can also be beneficial. If these measures don’t work, certain medications like beta-blockers and some others may be considered.
2. Orthostatic hypotension: This is fainting due to a sudden drop in blood pressure when a person stands from a sitting or lying position. Strategies to manage this include standing up slowly and dodging medications that can lower blood pressure. Wearing compression stockings to enhance blood flow, receiving intravenous fluids if they’re dehydrated, and using a medication called proamatine for severe cases can also help.
3. Cardiovascular disorders: If fainting is due to a heart condition, treatment should focus on addressing that underlying heart problem, usually overseen by a cardiologist.
The decision to admit a patient to the hospital after a fainting episode varies. In the U.S., about 80% of people who faint are admitted to the hospital, while in Canada and other countries, that number can be as low as 10%. Multiple guides have been designed to help doctors determine who needs to be admitted, usually based on risk factors unveiled in the patient’s history and exam.
Costs for evaluating fainting have grown notably in recent years. Roughly $2 billion is spent yearly in the U.S. on hospitalizing patients for this reason.
After hospital discharge, those with an unknown cause of fainting and no underlying heart disease typically have good outcomes. However, those with a heart condition should have regular check-ups with a primary care provider and a heart specialist.
What else can Syncope be?
When diagnosing fainting, or syncope, doctors need to consider other conditions that may present with similar symptoms. These can include:
- Seizure disorders, which can be identified by symptoms such as a feeling of déjà vu or a warning sign before a seizure (known as an aura), muscle stiffness followed by shaking (tonic-clonic activity), a long period of unconsciousness, incontinence, biting the tongue, or confusion after recovering.
- Low blood sugar or hypoglycemia
- Panic attacks, which may involve feelings of intense fear or dread, a rapid heartbeat (palpitations), a sense of suffocating or a shortness of breath (air hunger), and tingling around the mouth or fingertips.
These conditions can be differentiated by their specific symptoms, and so it’s important for doctors to conduct a comprehensive evaluation in order to decide the right diagnosis.
What to expect with Syncope
The outlook for recovery depends largely on what is causing the problem, so it’s crucial to pinpoint that cause. For those with a non-heart-related cause, the yearly death rate can vary from 0 to 12%. For patients with a heart-related cause, this rate can be between 18 to 33%. Therefore, identifying the cause is essential for understanding the individual’s prognosis.
Possible Complications When Diagnosed with Syncope
People can get hurt if they fall due to fainting, which is also known as syncope. The injuries can be more severe if they happen to be driving when the fainting episode occurs.
Possible Consequences:
- Injuries from falling due to fainting
- Severe injuries if driving during fainting episode
Preventing Syncope
It is particularly important to educate patients who have fainting spells caused by vasovagal syncope (a sudden drop in heart rate or blood pressure), orthostatic hypotension (a drop in blood pressure when standing up), and situational syncope (fainting triggered by specific situations).
After an episode of fainting, these patients need to know that they shouldn’t be driving and they should stay away from high places to stay safe.
Those with situational syncope, where certain situations cause them to faint, should be guided to avoid the situations that trigger these fainting episodes.
For patients with orthostatic hypotension, increasing fluid intake is beneficial to prevent low blood pressure and dehydration, which can cause fainting.
