It occurs when the brain does not receive enough blood flow and consciousness is lost.
Syncope is the medical term for fainting.
Usually, a slow heart rate causes a drop in blood pressure, which reduces the flow of blood to the brain.
In most cases of syncope, the sufferer recovers in a matter of seconds or minutes. A small number of people, mostly elderly, have episodes of fainting.
If you have trouble speaking, or have trouble moving your arm or leg after fainting, you should call for emergency help immediately. This can be a sign of a stroke.
What is neuronally mediated syncope?
Neurally mediated syncope (SMN) is the most common form of fainting and a frequent reason for visits to the emergency department.
It is also called reflex syncope, neurocardiogenic, vasovagal (VVS) or vasodepressor. It is benign and rarely requires medical treatment.
NMS is more common in children and young adults, although it can occur at any age.
It occurs when the part of the nervous system that regulates blood pressure and heart rate malfunctions in response to a trigger, such as emotional stress or pain.
The SMN usually occurs while standing and is usually preceded by a sensation of heat, nausea, stunning, tunnel vision or visual “greyness”.
Placing the person in a reclined position restores the blood flow and consciousness, and the seizure ends.
Situational syncope, which is a type of NMS, is related to certain physical functions, such as violent coughing (especially in men), laughing or swallowing.
Other disorders can cause syncope, which can also be a side effect of some medications.
Some types of syncope suggest a serious disorder:
- Those that occur with exercises
- Those associated with palpitations or irregularities of the heart
- Those associated with a family history of recurrent syncope or sudden death.
What is cardiac syncope?
Cardiac or cardiovascular syncope is caused by several heart conditions, such as bradycardia, tachycardia, or certain types of hypotension.
It can increase the risk of sudden cardiac death.
People suspected of having cardiac syncope but who do not have serious medical conditions can be treated as outpatients.
An additional evaluation is needed for hospitalized patients if serious medical conditions exist.
The conditions that can justify the evaluation and hospital treatment include various arrhythmic cardiac conditions, cardiac ischemia, severe aortic stenosis and pulmonary embolism.
If the evaluation suggests cardiac vascular abnormalities, an outpatient or implantable outpatient cardiac monitor may be necessary.
Heart failure, atrial fibrillation and other serious heart conditions can cause recurrent syncope in older adults, with a sharp increase after age 70.
Signs and symptoms of syncope
Common symptoms include:
- Warmth sensation.
- Blurry vision.
- Heaviness in the legs.
- Nausea and sometimes vomiting.
In addition to losing consciousness when the person faints, you can also submit:
- Have spasmodic shaking of your body.
- Have a weak pulse
- The experience of a drop in blood pressure.
What causes it?
Fainting often occurs due to a simple cause, such as:
- Standing up for long periods of time
- Feeling emotionally distressed
In rare cases, it may be the result of a health condition, such as:
- Heart disease (decreased blood flow to the heart or irregular heartbeat)
- Low blood sugar
- Panic attack.
- Problems that regulate blood pressure.
- Severe blood loss
Who is at greater risk of suffering syncope?
- Over 65 years of age
- Having heart disease, diabetes or high blood pressure
- The use of recreational drugs.
- Take certain medications, such as those used for blood pressure, insulin, oral medications for diabetes, diuretics, medications to control heart rhythm, or blood thinners.
- The smokers.
You should consult your doctor after fainting, who will ask you the following questions:
- What was he doing before fainting?
- How did you feel afterwards?
- You will have a physical exam.
- He will perform other tests, such as blood tests and electrocardiogram (ECG).
- He will send you an MRI (magnetic resonance imaging).
- It will focus on the medications you take.
- Consider the pre-existing medical conditions you may have.
- Compare your most recent fainting with similar episodes you had in the past.
This will help your doctor identify why you fainted and rule out certain health conditions. If seizures are suspected, your doctor may also do a test called an electroencephalogram (EEG).
Treatment for syncope
Patients with VVS and without a serious medical condition can usually be treated in an outpatient setting. For older adults, a comprehensive approach in collaboration with a geriatric expert can be useful.
For people who are dehydrated, it may be beneficial to increase salt and fluid intake to prevent syncope.
That recommendation, as well as the elimination or reduction of hypotensive and diuretic drugs, is also recommended when appropriate and safe for people who have experienced situational syncope.
The consumption of more salt and liquids may benefit most pediatric patients, but the results are not clear in people with NMS. Other changes in lifestyle, such as exercise, may also benefit pediatric patients.
Some patients of any age may need medication.
When it comes to driving after an episode of syncope, there are no restrictions for patients with VVS who did not have episodes of fainting in the previous year. Even so, it can be helpful for health care providers to discuss the laws, restrictions and regional management implications with all patients.
For athletes, a cardiovascular evaluation by a health care provider is recommended before resuming competitive sports.
People with syncope and a structural heart rhythm disorder should also see a specialist. Extended monitoring can help athletes with unexplained effort syncope.
If you are prone to syncope, you should:
- Avoid fatigue, hunger, and stress.
- Do not skip meals.
- Drink plenty of fluids.
- Avoid changing positions quickly, especially when you get up after sitting or lying down.
- Sleep with the feet of your bed elevated.
- Do not stand for long periods of time.
- Wear elastic stockings if necessary to prevent blood from accumulating in the legs.
- Diuretics and other medications (both prescription and over-the-counter) can contribute to the problem. So check with your doctor.
- Avoid caffeine and alcohol.
Any underlying serious health condition should be treated when a person faints:
- Elevate the legs to help increase the flow of blood to the brain.
- Loosen any tight clothing.
- Apply cold water to the face of the person.
- Turn the person’s head to the side to avoid vomiting or suffocation.
- A pregnant woman should lie on her left side to relieve pressure on the heart.
Recommendations of the AHA
People who experience the warning signs of fainting, dizziness, nausea and sweaty palms should sit or lie down.
Anyone with syncope should receive an initial evaluation, including detailed physical and history exams and a physician’s blood pressure and heart rate measurement.
An ECG (electrocardiogram) is also recommended as part of an initial evaluation to provide information about the cause of syncope.
The ECG is widely available and inexpensive, and can provide information about the potential and specific cause of syncope (eg, abnormal heart rhythms).
Other tests, such as exercise stress testing, the Holter monitor and an echocardiogram, may be needed to rule out other cardiac causes.
An ECG is also recommended for children and young adults with syncope.
Other non-invasive diagnostic tests may be needed if you are suspected of having congenital heart disease, cardiomyopathy, or a heart rhythm disorder.
If the initial evaluation is not clear, it may be helpful for patients to undergo a tilt test.
Blood pressure and heart rate will be measured while lying on a table and with the table tilted up.
People with NMS usually faint during bowing, due to the rapid fall in blood pressure and heart rate.
When people are placed on their backs again, the blood flow and consciousness are restored.
The future of syncope
Standardized national registries and large databases are needed to collect more data to better understand the incidence and prevalence of syncope, the risks and outcomes of patients, establish lifestyle policies and improve health care delivery.
Some studies have shown that, with recurrent episodes of fainting, quality of life is reduced in both adults and pediatric patients; however, better designed studies are needed that incorporate quality of life, loss of work and functional capacity.
In addition, more studies incorporate quality of life, loss of work and functional capacity as possible outcomes and better understand the relationship of syncope symptoms, causes and underlying diseases with various outcomes.