What is Syncope?
Updated: Dec 19, 2019
One minute you’re feeling a bit dizzy, the next thing you know, you’re flat on your back wondering what happened. About one third of people say they have fainted at least once. One of the most common reasons is syncope or else known as a "common faint".
Syncope is a sudden, complete loss of consciousness, described as fainting or passing out. In a typical syncope episode, a person will be standing and simply pass out with little to no warning. They will be unconscious for just a few minutes and may feel warm or appear flushed when they wake up. Syncope can happen if a person has a sudden drop in blood pressure, a drop in heart rate, or changes in the amount of blood in areas of the body. Syncope on its own may not be dangerous, aside from some risk of injury when passing out. However, there are some situations where syncope requires immediate medical attention, including:
Syncope during exercising or while laying down,
Palpitations or racing heart beat just before or during syncope,
Syncope combined with family history of sudden cardiac death or a prior diagnosis of abnormal heart rhythm or EKG,
Syncope combined with resting heart rate below 50.
When a patient visits Advanced Heart And Vein Center following fainting spells or repeat episodes of passing out, their doctor will confirm if it is syncope, identify what is causing it, and run tests to rule out any underlying heart issues. The doctor will ask a series of questions, such as if the patient completely passed out, if the episode was fast and short, if they lost postural tone (collapsed), how many times it has happened, and if any other symptoms occur along with passing out. These questions will help the physician diagnose if it is truly syncope or another health concern. Tests may include an EKG to check the heart rhythm and an echocardiogram (ultrasound of the heart) to rule out any structural issues with the heart.
Types of Syncope
There are several different types of syncope. The type you have depends on what causes the problem.
Vasovagal syncope (also called cardio-neurogenic syncope)
Vasovagal syncope is the most common type of syncope. It is caused by a sudden drop in blood pressure, which causes a drop in blood flow to the brain. When you stand up, gravity causes blood to settle in the lower part of your body, below your diaphragm. When that happens, the heart and autonomic nervous system (ANS) work to keep your blood pressure stable.
Some patients with vasovagal syncope have a condition called orthostatic hypotension. This condition keeps the blood vessels from getting smaller (as they should) when the patient stands. This causes blood to collect in the legs and leads to a quick drop in blood pressure.
Situational syncope is a type of vasovagal syncope. It happens only during certain situations that affect the nervous system and lead to syncope. Some of these situations are:
Intense emotional stress
Use of alcohol or drugs
Hyperventilation (breathing in too much oxygen and getting rid of too much carbon dioxide too quickly)
Coughing forcefully, turning the neck, or wearing a tight collar (carotid sinus hypersensitivity)
Urinating (miturition syncope)
Postural syncope (also called postural hypotension)
Postural syncope is caused by a sudden drop in blood pressure due to a quick change in position, such as from lying down to standing. Certain medications and dehydration can lead to this condition. Patients with this type of syncope usually have changes in their blood pressure that cause it to drop by at least 20 mmHg (systolic/top number) and at least 10 mmHg (diastolic/bottom number) when they stand.
Cardiac syncope is caused by a heart or blood vessel condition that affects blood flow to the brain. These conditions can include an abnormal heart rhythm (arrhythmia), obstructed blood flow in the heart due to structural heart disease (the way the heart is formed), blockage in the cardiac blood vessels (myocardial ischemia), valve disease, aortic stenosis, blood clot, or heart failure. If you have cardiac syncope, it is important to see a cardiologist for proper treatment.
Neurologic syncope is caused by a neurological condition such as seizure, stroke or transient ischemic attack (TIA). Other less common conditions that lead to neurologic syncope include migraines and normal pressure hydrocephalus
Postural Orthostatic Tachycardia Syndrome (POTS)
Postural-Orthostatic Tachycardia Syndrome is caused by a very fast heart rate (tachycardia) that happens when a person stands after sitting or lying down. The heart rate can speed up by 30 beats per minute or more. The increase usually happens within 10 minutes of standing. The condition is most common in women, but it can also occur in men.
Unknown Causes of Syncope
The cause of syncope is unknown In about one-third of patients. However, an increased risk of syncope is a side effect for some medications.
What are the symptoms of syncope?
The most common symptoms of syncope include:
Falling for no reason
Feeling drowsy or groggy
Fainting, especially after eating or exercising
Feeling unsteady or weak when standing
Changes in vision, such as seeing spots or having tunnel vision
Many times, patients feel an episode of syncope coming on. They have what are called “premonitory symptoms,” such as feeling lightheaded, nauseous, and heart palpitations (irregular heartbeats that feel like “fluttering” in the chest). If you have syncope, you will likely be able to keep from fainting if you sit or lie down and put your legs up if you feel these symptoms.
Syncope can be a sign of a more serious condition. So, it is important to get treatment right away after you have an episode of syncope. Most patients can prevent problems with syncope once they get an accurate diagnosis and proper treatment.
What causes syncope?
Syncope can be caused by many things. Many patients have a medical condition they may or may not know about that affects the nervous system or heart. You may also have a condition that affects blood flow through your body and causes your blood pressure to drop when you change positions (for example, going from lying down to standing).
Treatment options will vary greatly depending on each patient’s situation and the specific type of syncope diagnosed. For many patients, simply increasing water and sodium intake will reduce the frequency of syncope. Adequate hydration and sodium levels both help regulate blood volume, which in turn reduces the occurrence of syncope. Daily aerobic exercise is another factor that may help lessen the frequency of syncope. Other patients may require medication or even an implantable cardiac device, such as a pacemaker, for cardiac-related syncope.
If you have experienced repeat episodes of passing out, contact the Advanced Heart And Vein Center today to schedule an appointment with one of our physicians.