Syncope: Types, Causes, Symptoms, Diagnosis, Treatment and Prevention

Syncope is the medical term for fainting or losing consciousness. It occurs when your brain's blood supply abruptly and momentarily stops. The most common cause of fainting is a transient, benign sickness.

A potential reason for syncope could be:

• An abrupt decrease in blood pressure.
• A decrease in heart rate.
• Variations in the blood supply to different bodily parts.

If you faint, it can take you a few minutes or seconds to come to. Nevertheless, you may experience momentary fatigue or confusion. It just takes a few hours or minutes to recover.

Syncope could indicate a more serious illness. It's critical to get medical help as soon as possible after experiencing a syncope episode. When given the right diagnosis, most people can avoid issues associated with syncope.

Types of Syncope

There are several distinct types of syncope. These are enumerated here:

• Vasovagal syncope is often referred to as neurocardiogenic syncope This is the most common type of syncope. More than half of cases are due to vasovagal syncope.
• Situational syncope 
• Postrual syncope, Other names for the same condition are postural hypotension and orthostatic syncope.
• Cardiac syncope
• Nervous system-induced syncope
• POTS, or postural orthostatic tachycardia syndrome.
• Syncope without any obvious cause.

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Causes Of Syncope

Syncope occurs when the brain does not receive enough blood flow. The reason for this can vary based on the type of syncope. Many people may not even be aware that they have a physical illness that affects their nervous system or heart. It's also possible that you have a medical condition that causes your blood pressure to drop when you shift positions, such as from lying down to standing.

Vasovagal Syncope Causes

An abrupt drop in blood pressure causes less blood to reach the brain, which can lead to vasovagal syncope. It usually occurs after standing for an extended period or during emotionally trying times. 

Blood normally flows below the diaphragm in the lower body when you stand up due to gravity. During that period, the heart and autonomic nervous system work together to keep your blood pressure constant.

When you experience vasovagal syncope, your heart rate and blood pressure drop abnormally. You eventually pass out as a result of the brain receiving less blood. In most cases, vasovagal syncope is harmless.

Situational syncope causes 

Situational syncope is only caused by specific conditions that impair your nervous system. These conditions include:

• Body dryness.
• Severe mental exhaustion.
• Fear and anxiety.
• Use of drugs or alcohol; fear
• Anger
• Starvation.
• Exhaled carbon dioxide too soon and inhaled too much oxygen is known as hyperventilation.
• Tight collar wear, neck bending, or hacking (carotid sinus hypersensitivity).
• Micturition (syncope).

Postural syncope causes

Postural syncope, also known as postural hypotension or orthostatic hypotension, is a condition in which your blood pressure drops sharply when you suddenly change positions, such as standing up after lying down. Dehydration and some medications may cause this condition. People with this type of syncope frequently suffer a drop in blood pressure of at least 10 millimetres of mercury (diastolic/bottom number) and at least 20 millimetres of mercury (systolic/top number) when standing.

Cardiac syncope causes

Cardiac syncope may occur if you have a heart condition or blood vessel problem that affects blood flow to your brain. These situations could include:

• Arrhythmia, which is an erratic heartbeat.
• Cardiac obstruction brought on by the heart's structural characteristics (hypertrophic cardiomyopathy)
• Heart blockage in the veins carrying blood (myocardial ischemia)
• Disease of the valves
• Constriction, or aortic stenosis
• Blood clot
• Cardiac failure

If you have cardiac syncope, it's imperative that you see a cardiologist for appropriate therapy.

Neurologic syncope causes

Neurologic syncope can occur as a result of a neurological condition such as a seizure, stroke, or transient ischemic attack (TIA). Neurologic syncope can also be brought on by less prevalent conditions such headaches and normal pressure hydrocephalus.

Postural orthostatic tachycardia syndrome (POTS)

Postural orthostatic tachycardia syndrome patients may have tachycardia, or an abnormally fast heartbeat, when they stand up after sitting or lying down. Your heart rate may rise by as much as thirty beats per minute. The increase usually happens five minutes after standing. The disorder is more common in women and individuals who identify as AFAB, while it can also afflict men and persons who identify as AMAB.

Unknown causes of syncope

Thirty-three percent of syncope cases have an unknown cause. But certain medications have a side effect that makes syncope more likely. Make sure to follow up with your physician if you're not sure what's causing your syncope.

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Symptoms Of Syncope

The most common syncope symptoms are as follows:

• Feeling blackout
• Feeling dizzy.
• Feeling drowsy 
• Fainting, especially after a meal or exercise.
• Feeling unstable or feeble when standing.
• Alterations in vision, including seeing spots or tunnel vision.
• Headaches.

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Diagnosis  Of Syncope

See a medical professional if you think you could have syncope; they can refer you to a syncope expert for a comprehensive evaluation.

A syncope specialist will perform a physical examination as well as a comprehensive review of your medical history. They'll ask you detailed questions about your syncope episodes and symptoms, including where and when you faint and if you experience any symptoms before fainting.

They could take your pulse and blood pressure while you're sitting, standing, or even in a prone position.

Following that, one or more tests could be run to determine the cause of your syncope. These tests validate things like:

• The condition of your heart.
• How quickly your heart beats.
• The quantity or capacity of blood within your body.
• Blood flow in connection to the posture of your body.

The tests listed below are used to determine the causes of syncope:

• Laboratory testing: Hematologic or metabolic problems are detected by blood work.
• A test that records the electrical activity in your heart is called an electrocardiogram, or EKG.
• Exercise stress test: There are several stress tests that you may use to put your heart under strain, including those that require exercise or medication. Some stress tests do a heart ultrasound or look at abnormalities in the ECG. Stress testing can also be done with nuclear imaging.
• An ambulatory monitor is a wearable gadget that uses electrodes to record information about the beat and rhythm of your heart.
• An echocardiography is a test that uses sound waves to show you your heart's structure.
• Tilt table, also called head-up tilt test: A test in which you remain head-up and the provider tilts the table to various levels while monitoring your blood pressure and heart rate minute by minute or beat by beat. The test might identify abnormal cardiac reflexes that cause syncope.
• Testing your body's response to various stimuli, such as blood pressure, heart rate, blood flow, skin temperature, and perspiration, is done through an autonomic reflex test. These data can be used by your doctor to determine whether your autonomic nervous system is operating normally or if you have a nerve injury.

It may be necessary to perform additional tests such as computed tomography (CT) scans, electrophysiological studies, neurologic assessment, and autonomic nervous system testing. To rule out inner ear issues, you may need to have your vestibular function tested. Any further testing requirements will be discussed with you by your provider, along with the rationale behind them.

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Treatment  Of Syncope

If someone faints, take the following action:

• Check to make sure they are breathing.
• Make sure they lie down or sit with their head between their knees for at least 10 to 15 minutes.
• Give the person a cold water drink.

Your treatment options will be determined by the cause of your syncope as well as the results of your examination and tests. The therapy aims to stop syncope attacks.

Treatment options for syncope consist of:

• Taking prescription medications or changing what you already take.
• Wearing supportive clothes or compression stockings can improve blood circulation.
• Changing your diet: Your doctor may recommend eating small, frequent meals, increasing your potassium and salt consumption, drinking more water, avoiding alcohol and caffeine, and increasing your intake of potassium.
• Being extra cautious when standing up.
• Lift the head of your bed as you sleep. This can be achieved by adding more pillows or by placing risers under the legs of the bed head.
• Avoiding or adjusting the conditions or "triggers" (such as extended standing, extreme heat, or emotional stressors) that cause syncope.
• Training to control an increased heart rate via biofeedback.
• Getting treatment for a structural cardiac condition.
• Getting a pacemaker to keep your heart rate normal (but only in certain cases).
• Getting an implanted cardioverter defibrillator, or ICD. This device continuously monitors your heart rate and rhythm and corrects an irregular or rapid heartbeat (only for certain medical problems).

Together, you and your medical team will determine the best course of action for you after discussing your treatment options.

Medications for syncope include:

• Midodrine.
• Fludrocortisone 

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How is syncope preventable?

The onset of a syncope episode is often felt by the person. They also get nausea and dizziness. Heart palpitations are irregular heartbeats that feel like "fluttering" in the chest. It's possible that you won't pass out if you:

• When seated or lying down, lift your legs.
• Make a fist with your hands.
• Make your arms tense or tight.
• Fold your legs in half or clench your thighs together.

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