What is Supraventricular Tachycardia. How does SVT affect the heart’s normal rhythm. What are the common symptoms of SVT in infants and children. How is SVT diagnosed and treated. What are the long-term implications of SVT.

Understanding the Heart’s Structure and Function

The heart is a complex organ consisting of four chambers: two atria on top and two ventricles on the bottom. Each chamber plays a crucial role in pumping blood throughout the body. The right atrium receives deoxygenated blood from the body and sends it to the right ventricle, which then pumps it to the lungs for oxygenation. The oxygenated blood returns to the left atrium and is then pumped by the left ventricle to the rest of the body.

For optimal functioning, the heart’s chambers must contract in a specific sequence. The atria contract first, followed by a brief pause, allowing the ventricles to fill with blood before they pump. This coordinated action ensures efficient blood flow throughout the body.

The Heart’s Electrical System: The Conductor of Rhythm

At the core of the heart’s functionality lies its electrical system. The sinus node, located at the top of the right atrium, serves as the heart’s natural pacemaker. It generates electrical impulses that spread through both atria, similar to ripples in water, signaling them to contract and push blood into the ventricles.

From there, the electrical signal travels to the atrioventricular (AV) node and then down through specialized pathways that branch into the right and left ventricles. This electrical impulse stimulates the ventricles to contract, pumping blood to the lungs and body. This entire cycle constitutes a single heartbeat.

In a healthy adult, the resting heart rate typically ranges from 60 to 100 beats per minute. However, infants and children naturally have faster heart rates compared to adults.

Supraventricular Tachycardia: When the Heart Races

Supraventricular tachycardia (SVT) is a condition characterized by an abnormally rapid heart rhythm that originates above the ventricles. In SVT, the heart’s electrical signals do not follow the regular pathway from the atria to the ventricles, resulting in an accelerated heart rate.

How fast can the heart beat during an SVT episode? In children, SVT can cause the heart to beat at rates of 180 to 220 beats per minute, while in infants, it can reach up to 300 beats per minute. These episodes can occur suddenly and may last for varying durations, from just a few minutes to several hours.

Is SVT a lifelong condition? SVT can affect individuals of any age and may be the only heart-related issue a person experiences. However, if left untreated, it can impact the heart’s ability to pump blood effectively.

Triggers and Types of SVT

SVT episodes can occur spontaneously at rest or be triggered by physical exertion. It’s important to note that there are different types of SVT, each with its own characteristics. A pediatric cardiologist can provide more detailed information about the specific type of SVT affecting a child.

Recognizing SVT: Signs and Symptoms

The symptoms of SVT can vary depending on the age of the individual affected. Infants, unable to verbalize their discomfort, may display non-specific signs that could be mistaken for other illnesses.

SVT Symptoms in Infants

• Irritability
• Poor feeding
• Excessive sweating during feeding
• Rapid breathing (tachypnea)
• Pale or generally ill appearance

SVT Symptoms in Toddlers and Older Children

As children grow older, they may be able to describe more specific symptoms related to SVT:

• Sensation of heart pounding
• Feeling of heart “beeping” in the chest
• Awareness of a rapid or irregular heartbeat
• Sensation of pulse in the throat

Diagnosing SVT: Medical Tests and Procedures

If a healthcare provider suspects SVT, they will typically refer the patient to a pediatric cardiologist specializing in heart rhythm disorders. The cardiologist may recommend several diagnostic tests to confirm the presence of SVT and determine its specific type.

Electrocardiogram (ECG/EKG)

An ECG is a non-invasive test that records the heart’s electrical activity. How is an ECG performed? The procedure involves the following steps:

1. The child’s shirt is removed
2. Small adhesive electrodes are placed on the child’s chest
3. These electrodes are connected by wires to an ECG machine
4. The machine records the heart’s electrical activity
5. After the test, the electrodes are removed from the child’s chest

The ECG provides immediate results and can help identify abnormal electrical patterns in the heart. While the test is painless, it requires the child to remain calm and still during the procedure.

Holter Monitor

A Holter monitor is essentially a portable ECG device that records the heart’s rhythm continuously for 24 hours or more. This test is particularly useful for detecting intermittent arrhythmias that may not be captured during a standard ECG.

Who benefits most from Holter monitoring? This test is often recommended for children who may have heart rhythm problems but are unable to articulate their symptoms clearly.

Event Monitor

An event monitor is a specialized device that can be worn for up to 30 days. It allows the patient or caregiver to record the heart rhythm when symptoms occur by pressing a button. The recordings are then transmitted to a monitoring service and subsequently reviewed by the pediatric cardiologist.

Treatment Options for SVT: From Simple Techniques to Advanced Interventions

The treatment approach for SVT can vary depending on the frequency and severity of episodes, as well as the patient’s age and overall health. Pediatric cardiologists may recommend a range of treatments, from simple maneuvers to medications or procedures.

Vagal Maneuvers: Natural Ways to Slow the Heart

The vagus nerve plays a crucial role in regulating heart rate. Stimulating this nerve can help slow down a racing heart during an SVT episode. Older children may be taught to perform vagal maneuvers, which include:

• Blowing through a straw
• Performing a headstand
• Bearing down or simulating a bowel movement

These techniques can be effective in terminating some SVT episodes, particularly in older children who can follow instructions.

Medications: Controlling SVT Episodes

In cases where vagal maneuvers are ineffective or impractical, medications may be prescribed to manage SVT. The most commonly used class of drugs for this purpose is beta blockers.

How do beta blockers work in treating SVT? These medications help control SVT by:

• Decreasing the frequency of SVT episodes
• Helping to control symptoms
• Preventing the heart rate from becoming excessively rapid

It’s important to note that while medications can effectively manage SVT, they do not cure the underlying condition. If beta blockers prove ineffective, the cardiologist may consider other types of antiarrhythmic medications.

Advanced Treatment Options for Persistent SVT

In cases where SVT episodes are frequent, severe, or unresponsive to conventional treatments, more advanced interventions may be considered.

Catheter Ablation: A Minimally Invasive Approach

Catheter ablation is a procedure that aims to eliminate the abnormal electrical pathway causing SVT. During this procedure, thin, flexible tubes called catheters are inserted through blood vessels and guided to the heart. The cardiologist then uses these catheters to identify and eliminate the problematic electrical pathway.

What are the success rates of catheter ablation for SVT? While success rates can vary depending on the specific type of SVT, many patients experience significant improvement or complete resolution of their symptoms following this procedure.

Cardioversion: Resetting the Heart’s Rhythm

In some cases, particularly when SVT episodes are prolonged or causing significant symptoms, cardioversion may be necessary. This procedure involves delivering a controlled electrical shock to the heart to reset its rhythm.

Cardioversion can be performed in two ways:

• Electrical cardioversion: A brief electrical shock is delivered through paddles or patches on the chest
• Chemical cardioversion: Intravenous medications are used to restore normal heart rhythm

Living with SVT: Long-term Management and Lifestyle Considerations

While SVT can be a concerning condition, many individuals with this arrhythmia lead normal, active lives with proper management. Long-term care for SVT often involves a combination of medical supervision, lifestyle modifications, and self-management strategies.

Regular Medical Follow-ups

Individuals with SVT should maintain regular check-ups with their cardiologist to monitor their condition and adjust treatment as necessary. These visits may include:

• Periodic ECGs or other heart rhythm monitoring
• Assessment of medication effectiveness and side effects
• Evaluation of overall cardiovascular health

Lifestyle Modifications

Certain lifestyle changes can help reduce the frequency and severity of SVT episodes:

• Stress management techniques such as meditation or yoga
• Regular exercise, as approved by the cardiologist
• Avoiding known triggers, which may include caffeine or alcohol in some individuals
• Maintaining a healthy sleep schedule

Self-Management Strategies

Empowering patients and their families with knowledge and skills to manage SVT is crucial. This may include:

• Learning to recognize early signs of an SVT episode
• Practicing vagal maneuvers (for older children and adults)
• Keeping a log of SVT episodes and potential triggers
• Understanding when to seek emergency medical attention

Psychosocial Aspects of Living with SVT

Living with a chronic heart condition like SVT can have psychological and social impacts, particularly for children and adolescents. It’s important to address these aspects as part of comprehensive care.

Emotional Well-being

Children and adolescents with SVT may experience anxiety or fear related to their condition. Providing emotional support and access to mental health resources when needed is crucial. This may include:

• Counseling or therapy to address anxiety or depression
• Support groups for individuals with heart conditions
• Age-appropriate education about SVT to empower patients

School and Social Life

SVT should not significantly limit a child’s participation in school or social activities. However, some considerations may include:

• Educating school staff about the child’s condition and emergency procedures
• Ensuring appropriate accommodations for physical education classes if necessary
• Encouraging normal social interactions while being mindful of the child’s health needs

Research and Future Directions in SVT Management

The field of cardiac electrophysiology is continuously evolving, with ongoing research aimed at improving our understanding and treatment of SVT and other arrhythmias.

Emerging Technologies

Advancements in technology are enhancing our ability to diagnose and treat SVT. Some areas of development include:

• Improved mapping systems for more precise catheter ablation procedures
• Wearable devices for continuous heart rhythm monitoring
• Artificial intelligence algorithms for early detection of arrhythmias

Genetic Research

Understanding the genetic factors contributing to SVT may lead to more personalized treatment approaches. Ongoing studies are exploring:

• Genetic markers associated with increased SVT risk
• Potential gene therapies for certain types of arrhythmias
• Pharmacogenomics to predict individual responses to antiarrhythmic medications

As research progresses, we can anticipate more targeted and effective treatments for individuals with SVT, potentially improving outcomes and quality of life for those affected by this condition.

Supraventricular Tachycardia (SVT)

The Heart as a Pump

The heart has four chambers. The two on the top are called the atria and the two on the bottom are called the ventricles. The right atrium receives blood from the body and sends it to the right ventricle which pumps the blood to the lungs. The blood returns from the lungs to the left atrium which sends blood to the left ventricle which pumps blood back to the body. For the heart to function as a good pump, the atria must squeeze first, then pause and allow the bottom chambers to pump (Picture 1).

The Heart’s Electrical System

Next, we must understand how the conduction system is built. The normal “pacemaker” of the heart is called the sinus node. It is located at the top of the right atrium. An impulse, or electrical signal, passes from the sinus node through both atria, much like ripples from a pebble thrown into the water. The electrical signal tells the atria to squeeze blood into the ventricles. The signal then travels to the AV node and then down through the electrical pathway. This pathway branches into the right and left ventricles. The electrical impulse stimulates the ventricles to pump blood out to the lungs and body. This cycle is called a heartbeat.

The normal adult heart rate is 60 to 100 beats per minute while at rest. Infants and children have a faster heart rate than adults. 

Supraventricular Tachycardia

Supraventricular tachycardia (soo pruh ven TRIK yuh ler tack ih KAR dee uh), also called SVT, is a very fast heart rhythm that does not follow the regular pathway from the atria to the ventricles. It can cause a heart to beat at rates of 180 to 220 beats per minute in children and up to 300 beats per minute in infants. It can happen at any age and may be your child’s only heart problem. SVT can start and stop quickly. It may last for minutes or continue for hours. If it is not treated, the heart’s ability to pump normally is affected. SVT can occur at rest or be triggered by exercise. There are different types of SVT so your pediatric cardiologist will give more detail on which type of SVT your child has.

Common Signs and Symptoms

Infants are not able to tell you if the following signs or symptoms happen. They are not unique to SVT. They can occur with other illness.

• irritable
• poor feeding
• baby sweats a lot with feeding
• fast breathing (tachypnea)
• pale or generally ill appearing

Toddlers and older children may be able to tell you if they are having the following symptoms:

• heart pounds
• heart ‘beeping’ in chest
• feels a rapid or irregular heartbeat
• feeling pulses in their throat

Diagnostic Tests

If your child’s doctor thinks your child has SVT, you will be sent to a pediatric cardiologist who treats heart rhythm problems. They may recommend the following tests:

ECG/EKG (Electrocardiogram)

This test records the heart rhythm and can be done in a doctor’s office.

1. The child’s shirt is removed.
2. Small stickers are placed on the child’s chest. 
3. The stickers are connected by wires to an ECG machine.
4. The ECG machine records the electrical activity in the heart.
5. The stickers are removed from your child’s chest

You will get results as soon as the test is done. The test helps find abnormal electrical activity in the heart. The test does not hurt, but your child needs to be calm and rest during the test.

Holter Monitor

This test is an ECG that is recorded for 24 hours or more. The Holter is a monitor that your child goes home with. It records the heart rhythm during the day and while sleeping. This test is often used in children who may have a heart rhythm problem but are not able to tell you how they are feeling or what may be wrong.

Event Monitor

This is a special type of monitor. It can be worn for up to 30 days and allows your child to press a button to record the rhythm when they have symptoms. The recordings are sent to a monitoring service and then reported to the pediatric cardiologist for review. 

Treatment

Your child’s pediatric cardiologist may recommend medicines or a procedure. Some of the choices are listed below. 

Vagal Maneuvers

The vagus nerve is a nerve in the body that travels from the brain down through the chest and into the abdomen. The vagus nerve can slow down the heart rate. Older children may be able to slow their heart rate by trying one or more of the following:   

• blowing through a straw
• doing a headstand
• bearing down or pretending to have a bowel movement

Medicines

Your child’s pediatric cardiologist may prescribe a medicine they take each day to treat SVT.

• Medicine does not cure SVT. It decreases the number of events and helps control symptoms by keeping the heart rate from beating too fast. This type of medicine is called a beta blocker.
• If the beta blocker does not work, another type of medicine may be used. These are called anti-arrhythmic medicines.

Ablation

This is an outpatient procedure done by a pediatric electrophysiologist (a heart doctor that specializes in abnormal rhythms). It is performed in the heart catheterization (KATH ett urr izz AY shun) lab. During the procedure, special equipment finds the electrical pathway in the heart that causes SVT. Ablation may be a choice if the medicine does not work or if your child still has frequent SVT symptoms. Your child will receive sedation or general anesthesia for the procedure. 

Home Monitoring

For infants, you will be instructed to place your hand on your baby’s chest while they are calm and count their heart rate for one minute at least one time each day.

Children may be able to tell you if their heart is beating too fast.

• Not eating well
• Lethargic (tiredness)
• Irritable
• Excessive sweating
• Shortness of breath
• Dizziness
• Palpitations (feeling of the heart beating fast or fluttering)

If your child has SVT at home that is not relieved by vagal maneuvers or their medicine, get medical care. Go to your local emergency room or call 911.

In the emergency room, your child may get adenosine. This medicine goes through an IV, a tube that goes into the child’s vein and stops a fast heart rate so the heart can resume a normal rhythm. The medicine does this by slowing the speed of the electrical signal that is traveling through the heart.

Living with SVT

Most children with SVT live completely normal lives and have a normal life expectancy. However, it is important to routinely meet with your child’s pediatric cardiologist for continued SVT care.

• Keep important emergency phone numbers and doctor contact information in a place where you can easily access them.
• Write down all your questions as you think of them. Bring this list with you when you see the doctor.

Supraventricular Tachycardia (SVT) (PDF)

HH-I-376 | Copyright 2020, Nationwide Children’s Hospital

What is supraventricular tachycardia (SVT)?

What is SVT?

Supraventricular tachycardia (SVT) is a fast, abnormal heart rhythm that originates from the atria (top chambers of the heart). It is an umbrella term for several different abnormal heart rhythms. Some of these heart rhythms are intermittent, and others are always present. Read on to learn more about SVT, its causes and how we diagnose it. We then discuss SVT treatment in detail so you can make an informed choice about your care.

The normal heartbeat

Our heart is designed to beat efficiently and at the right time through small electric currents that pass through the muscle and tissue of the heart. These small impulses originate from the heart’s “inbuilt pacemaker” – known as the Sino-atrial Node (or SA node). Impulses from the SA node pass down an electrical pathway via a second relay station (AV node) to tell the bottom of the heart to beat. This system ensures that both the atria and the ventricles (bottom chambers) beat at the appropriate time to ensure the blood is pumped efficiently around the body.

Are there different causes of SVT?

An SVT is caused generally in 3 ways:

A part or parts of the atria (not the SA node) gives off impulses which can then pass through the heart, overriding the SA node and causing the heart to beat faster (atrial tachycardia)

An extra bit of wiring exists within the AV node allowing a short circuit and fast heart rhythm (AVNRT)

There is an extra bit of wiring present in the heart between the atria and ventricles or within the atria. This can lead to a short circuit, causing a fast heart rhythm (AVRT) or Wolff-Parkinson-White (WPW) syndrome

What are the symptoms of an SVT?

Most people find that they experience palpitations (feeling a fast fluttering of your heart) or shortness of breath. Some people are aware of their heart beating in their throat or ear. You may notice that you can’t do as much physical activity as you could before. In some cases, it can make you feel dizzy and light-headed. Sometimes patients have symptoms for many years and have been labelled as having panic attacks.

Is an SVT dangerous?

Even though the heart can beat very fast with an SVT, they are usually not dangerous if the heart is structurally normal. However, certain SVTs occur due to an extra pathway between the top and bottom of the heart. Though it is rare, this may be dangerous.

How is an SVT diagnosed?

The unpredictable nature of an SVT can present a diagnostic challenge. It is often difficult to predict how long an episode will last and when it will terminate. We will take a detailed account of your symptoms as an SVT typically starts and stops abruptly. So, your history can be very informative. Generally, we diagnose most SVTs with an ECG (heart rhythm trace). An SVT will interrupt the normal heart rhythm and be visible on an ECG. Then again, the SVT may have stopped by the time we perform an ECG.

ECG

The ECG could provide clues as to the cause but may also be completely normal. Therefore, your cardiologist might perform a longer heart rhythm trace called a Holter or ambulatory ECG monitor. We attach you to an ECG recorder or patch monitor for a prolonged period – usually 24-48 hours, but it can last up to a week. While you wear the monitor, you go about your day as usual, and it records any symptoms you have. We can then match it to what your heart rhythm was doing at that moment.

Implantable loop recorder

In patients with infrequent episodes, we can implant a small device called an implantable loop recorder under the skin (Reveal LinQ monitor). This device can remain in place for up to 3 years. We implant this in the outpatient setting under local anaesthetic, and the procedure only takes several minutes. Wireless technology means we can stay informed of your heart rhythm without you having to make frequent trips to the hospital.

Additional tests

In addition, we will perform blood tests to ensure there is no other reason for your racing heart. For example, your blood salt and hormone levels can affect your heart’s electrical system. We may also perform an ultrasound scan of the heart (an echo) to see if there are any structural abnormalities and obtain an idea of how well the heart is pumping.

Are there any triggers for SVT?

Caffeine, alcohol, sleep deprivation, and stress are common triggers of SVT episodes. However, often there is no particular trigger, and episodes can start spontaneously.

How is an SVT treated?

SVT treatment depends on what is causing the SVT and the impact on your life. I.e. how often it happens and how badly it affects you when it does. Some people find that SVT does not affect them very much, and episodes are infrequent. Essentially there are three types of SVT treatment: conservative measures, medications, and catheter ablation.

Conservative measures

These may include holding your breath in a particular way or using cold water. Whilst effective in some patients for stopping the SVT, they may not work. We call these vagal manoeuvres. Visit our blog to learn more about these and other lifestyle changes to help manage an arrhythmia.

Medications

If symptoms are intrusive or frequent, we may offer you medications which can be used on an ‘as required’ basis and taken when the SVT occurs to settle the heart rhythm back to normal. Alternatively, you can use these medications regularly to try and prevent episodes. However, these medications may not be effective for everyone. They can also cause side effects in some. Also, some patients continue to experience episodes despite being on medications. Commonly used drugs include beta-blockers, verapamil, flecainide and sotalol.

Catheter ablation

Nowadays, the first-line treatment for SVT is Catheter Ablation. This SVT treatment is a minimally invasive procedure (not surgery). We pass fine wires from the vein at the top of your leg to the heart. During catheter ablation, we can do a detailed study of your heart’s electrical activity (an EP study) to identify the exact part of the heart that is causing the abnormal electrical activity.

We do this using electrical signals and sometimes a computer-generated virtual map of your heart. During this procedure, we attempt to trigger your SVT in a controlled environment, which helps us make the correct diagnosis. Once we diagnose you with SVT, we deliver high-frequency energy to the tiny area in the heart causing the problem to destroy or modify the abnormal cells. This prevents them from interfering with the electrical pathway of the heart.

Catheter ablation has a success rate of over 90%. We can perform it under local anaesthetic with sedation or a general anaesthetic, usually as a day case. It is a very safe procedure, and the risks of serious complications are low (1-2%). These include bleeding at the top of the leg, bleeding around the heart, and, rarely, a permanent pacemaker.

clinical death from the point of view of medicine – Moscow 24, 06/09/2015

Photo: M24.ru/Mikhail Sipko

Woland’s mouth, perfectly describe the feelings of most people. Probably, there is no person who would not be afraid of death. But along with the big death, there is a small death – clinical. What is it, why people who have experienced clinical death often see the divine light and is it not a delayed path to paradise – in the material M24.ru.

Clinical death from the point of view of medicine

The problems of studying clinical death as a borderline state between life and death remain among the most important in modern medicine. Unraveling many of its mysteries is also difficult because many people who have experienced clinical death do not fully recover, and more than half of patients with a similar condition cannot be resuscitated, and they die for real – biologically.

So, clinical death is a condition accompanied by cardiac arrest, or asystole (a condition in which various parts of the heart stop contracting first, and then cardiac arrest occurs), respiratory arrest and deep, or beyond, cerebral coma. With the first two points, everything is clear, but about whom it is worth explaining in more detail. Usually doctors in Russia use the so-called Glasgow scale. According to the 15-point system, the reaction of opening the eyes, as well as motor and speech reactions, is evaluated. 15 points on this scale correspond to clear consciousness, and the minimum score – 3, when the brain does not respond to any kind of external influence, corresponds to transcendental coma.

After stopping breathing and cardiac activity, a person does not die immediately. Almost instantly, consciousness is turned off, because the brain does not receive oxygen and its oxygen starvation sets in. But nevertheless, in a short period of time, from three to six minutes, he can still be saved. Approximately three minutes after breathing stops, cell death begins in the cerebral cortex, the so-called decortication. The cerebral cortex is responsible for higher nervous activity and, after decortication, resuscitation measures, although they can be successful, a person can be doomed to a vegetative existence.

Photo: TASS/Sergey Bobylev

A few minutes later, cells of other parts of the brain begin to die – in the thalamus, hippocampus, cerebral hemispheres. The state in which all parts of the brain have lost functional neurons is called decerebration and actually corresponds to the concept of biological death. That is, the revival of people after decerebration is in principle possible, but a person will be doomed for the rest of his life to be on artificial lung ventilation and other life-sustaining procedures for a long time.

The fact is that the vital (vital – M24.ru) centers are located in the medulla oblongata, which regulates breathing, heartbeat, cardiovascular tone, as well as unconditioned reflexes like sneezing. With oxygen starvation, the medulla oblongata, which is actually a continuation of the spinal cord, dies one of the last sections of the brain. However, although the vital centers may not be damaged, by then decortication will have set in, making it impossible to return to normal life.

Other human organs such as the heart, lungs, liver and kidneys can survive much longer without oxygen. Therefore, one should not be surprised at the transplantation, for example, of kidneys taken from a patient with an already brain dead. Despite the death of the brain, the kidneys are still in working condition for some time. And the muscles and cells of the intestine live without oxygen for six hours.

Currently, methods have been developed that can increase the duration of clinical death up to two hours. This effect is achieved with the help of hypothermia, that is, artificial cooling of the body.

Photo: TASS/Vladimir Smirnov

As a rule (unless, of course, it happens in a clinic under the supervision of doctors), it is rather difficult to determine exactly when the cardiac arrest occurred. According to current regulations, doctors are required to carry out resuscitation measures: heart massage, artificial respiration for 30 minutes from the start. If during this time it was not possible to resuscitate the patient, then biological death is stated.

However, there are several signs of biological death that appear as early as 10–15 minutes after brain death. First, Beloglazov’s symptom appears (when pressing on the eyeball, the pupil becomes similar to a cat’s), and then the cornea of ​​​​the eyes dries up. If these symptoms are present, resuscitation is not carried out.

How many people survive clinical death safely

It may seem that most people who find themselves in a state of near death come out of it safely. However, this is not the case, only three to four percent of patients can be resuscitated, after which they return to normal life and do not suffer from any mental disorders or loss of body functions.

Another six to seven percent of patients, being resuscitated, nevertheless do not fully recover, suffer from various brain lesions. The vast majority of patients die.

Such sad statistics are largely due to two reasons. The first of them – clinical death can occur not under the supervision of doctors, but, for example, in the country, from where the nearest hospital is at least half an hour away. In this case, the doctors will come when it will be impossible to save the person. Sometimes it is impossible to timely defibrillate when ventricular fibrillation occurs.

“Special Report”: Beyond the Boundaries

The second reason is the nature of the damage to the body during clinical death. When it comes to massive blood loss, resuscitation is almost always unsuccessful. The same applies to critical myocardial damage in a heart attack.

For example, if more than 40 percent of the myocardium is affected as a result of blockage of one of the coronary arteries, death is inevitable, because the body cannot live without heart muscles, no matter what resuscitation measures are taken.

Thus, it is possible to increase the survival rate in case of clinical death mainly by equipping crowded places with defibrillators, as well as by organizing flying ambulance crews in hard-to-reach areas.

Clinical death for patients

If clinical death for doctors is an emergency, in which it is necessary to urgently resort to resuscitation, then for patients it often seems like a path to the bright world. Many near-death survivors have reported seeing light at the end of a tunnel, some meeting their long-dead relatives, others looking at the earth from a bird’s eye view.

“I had a light (yes, I know how it sounds), and I seemed to see everything from the outside. It was bliss, or something. No pain for the first time in so much time. “someone else’s life and now I’m just slipping back into my skin, my life – the only one in which I’m comfortable. It’s a little tight, but it’s a pleasant tightness, like a frayed pair of jeans that you’ve been wearing for years,” says Lydia, one of the patients, who suffered clinical death.

Photo: M24.ru/Mikhail Sipko

It is this feature of clinical death, its ability to evoke vivid images, that is still the subject of much controversy. From a purely scientific point of view, what is happening is described quite simply: brain hypoxia occurs, which leads to hallucinations in the actual absence of consciousness. What kind of images arise in a person in this state is a strictly individual question. The mechanism of occurrence of hallucinations has not yet been fully elucidated.

At one time the endorphin theory was very popular. According to her, much of what people experience near death can be attributed to the release of endorphins due to extreme stress. Since endorphins are responsible for getting pleasure, and in particular even for orgasm, it is easy to guess that many people who survived clinical death considered ordinary life after it to be only a burdensome routine. However, in recent years, this theory has been debunked because researchers have found no evidence that endorphins are released during clinical death.

There is also a religious point of view. As, however, in any cases that are inexplicable from the standpoint of modern science. Many people (there are scientists among them) tend to believe that after death a person goes to heaven or hell, and the hallucinations that survivors of near-death experience saw are only proof that hell or heaven exists, like the afterlife in general. It is extremely difficult to give any assessment to these views.

Nevertheless, not all people experienced heavenly bliss at clinical death.

“I suffered clinical death twice in less than one month. I didn’t see anything. When they returned, I realized that I was nowhere, in non-existence. I didn’t have anything there. I concluded that there you get rid of everything by completely losing yourself , probably, together with the soul. Now death does not really bother me, but I enjoy life, “accountant Andrey cites his experience.

In general, studies have shown that at the time of human death, the body loses little in weight (literally a few grams). Adherents of religions hastened to assure mankind that at this moment the soul is separated from the human body. However, the scientific approach says that the weight of the human body changes due to chemical processes occurring in the brain at the time of death.

Physician’s opinion

Current standards require resuscitation within 30 minutes of the last heartbeat. Resuscitation stops when the human brain dies, namely on registration on the EEG. I have personally resuscitated a patient once who went into cardiac arrest. In my opinion, the stories of people who have experienced clinical death are, in most cases, a myth or fiction. I have never heard such stories from patients of our medical institution. As well as there were no such stories from colleagues.

Moreover, people tend to call clinical death completely different conditions. It is possible that the people who allegedly had it did not actually die, they just had a syncopal state, that is, fainting.

Cardiovascular diseases remain the main cause that leads to clinical death (as well as to death in general). Generally speaking, such statistics are not kept, but it must be clearly understood that clinical death occurs first, and then biological. Since the first place in mortality in Russia is occupied by diseases of the heart and blood vessels, it is logical to assume that they most often lead to clinical death.

Dmitry Yeletskov

anesthesiologist-resuscitator, Volgograd

One way or another, the phenomenon of near-death experience deserves careful study. And it is quite difficult for scientists, because in addition to the fact that it is necessary to establish which chemical processes in the brain lead to the appearance of certain hallucinations, it is also necessary to distinguish truth from fiction.

science coma patients scientific issues clinical death

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How to avoid visual impairment: advice from a specialist of the SUSU Medical Center

1. News
2. 2020

October

4. 08
5. How to avoid visual impairment: advice from a specialist of the SUSU Medical Center

08.10.2020

Today is World Sight Day. Our reality is this: the modern way of life leads to deterioration of vision in many people. Reasons – working at a computer monitor, using gadgets, improper nutrition, lack of rest …

Eyes are one of the most important sense organs, a person receives up to 90% of information through them. The quality of life, the ability to work and serve oneself depends on their proper functioning.

Director of the SUSU Medical Center Olga Veselova told how to avoid early visual impairment.

You need to follow a few simple rules:

• In urban conditions, the air is very dry, and this is harmful to the organ of vision. Therefore, it is recommended to use a humidifier at home.
• Walk outside every day. Oxygen has a beneficial effect on the entire body, including the eyes. During walks, the need to concentrate on one point disappears, the eyes relax.
• Smoking and alcohol damage the optic nerve and disrupt the blood supply to the retina. People with bad habits often have a violation of color perception, a decrease in visual acuity. Therefore, it is recommended to give up bad habits.
• Takes care of the sufficient intake of vitamins in the body. Vitamin A, E, C are especially important for vision. It is useful to eat blueberries, carrots, and currants. With a lack of vitamins in the diet, you need to take multivitamin preparations.

Director of the SUSU Medical Center Olga Veselova

How to read correctly?

• When reading literature, lighting should be sufficient. The best option is the light that gives an incandescent lamp of 75-90 watts. Brighter is not needed, as this will increase the load on the eyes, because the light will be reflected from the white paper. It is for this reason that you should not read outside on a sunny day.
• It is not recommended to read lying down at all! In this position, the flow of oxygen to the brain slows down. Therefore, it is necessary to enjoy literature only while sitting. In this case, the legs should be exactly on the floor, knees and hips bent at an angle of 90°.
• The distance from the eyes to the book must be at least 30 cm. In the sitting position, this can be easily checked by placing the elbow on the table, while the palm should be near the eyes.
• Choose books with large enough print so you don’t have to strain your eyes.
• Every 20-30 minutes you need to take your eyes off the book and look into the distance. At least 1-2 minutes of rest will reduce the load on vision.

How to work at a computer?

Computer work puts more strain on the eyes than TV or a book, for example. The blue light from the monitor, its brightness, font size, distance to the screen negatively affect the eyes. It is recommended to spend no more than 6 hours in front of the computer, but this is not always possible.

To avoid problems associated with visual impairment, you need to know the rules of working at a computer:

• The most important thing is the distance to the monitor. The screen should be slightly below eye level, located at arm’s length.
• Sit straight. You can not strain your neck or arms, this disrupts blood circulation.
• We recommend that you lower the brightness of your smartphone screen and computer monitor. This is especially important when the room is dark – a sharp contrast in brightness creates a big strain on the eyes.
• When working at a computer for a long time, it is very important to take breaks every 30-40 minutes, doing exercises for the eyes or looking out the window. And when looking at the monitor, you need to blink regularly, this helps to avoid dryness.
• To neutralize harmful radiation from the screen, it is recommended to use special glasses or lenses.

Eye exercises

Visual acuity depends on the correct functioning of the oculomotor muscles. When a person looks at the screen of gadgets for a long time, they do not work. Because of this, they weaken and cannot perform their functions. Therefore, special exercises for the eyes not only help prevent visual impairment, but can restore its sharpness.