Cardiac arrest / cardiac arrest
Synonyms in the broader sense
Resuscitation, Cardiopulmonary Resuscitation, Cardiopulmonary Resuscitation
English: asystole, flatline
definition
Cardiac arrest correctly describes cardiovascular arrest in which the heart no longer pumps blood into the circulation.
In the case of cardiac arrest, the person concerned becomes dizzy after a few seconds, after half a minute there is a loss of consciousness.
Breathing stops after two minutes, and the first brain damage occurs another two minutes later.
Basically, cardiac arrest can occur due to many heart diseases.
These include heart attacks, cardiac arrhythmias, heart failure, etc.
An electrical accident can also trigger cardiac arrest.
For particularly complex operations, cardiac arrest can also be triggered with medication for a planned time.
Types of cardiac arrest
At the Cardiac arrest or Cardiac arrest (the terms are often used synonymously) a distinction is made between whether it is in heart or there is no electrical activity.
Normally, the heartbeat is triggered by constant electrical excitation of the heart muscle cells. The so-called hyperdynamic form of cardiac arrest / cardiac arrest leads to "circling" electrical excitations, i.e. the heart muscle cells are all excited, but not synchronously. You can imagine it like an orchestra. This is usually coordinated by the conductor in such a way that harmonious sounds are created.
In the heart is that Sinus node the conductor, he sets the pace. With the circling excitement, all the instruments would play, but they would not pay attention to the conductor and no harmonic sounds would come about that represent the normal heartbeat.
At the hyperdynamic cardiac arrest/ Cardiac arrest So the heart twitches, but there is no beat that actually pumps blood.
These are examples of hyperdynamic cardiac arrests / cardiac arrests Ventricular fibrillation and the pulseless ventricular tachycardia. With the latter, the heart beats in a fairly orderly manner, but so fast that it cannot build up any pumping capacity.
The other form of the Cardiac arrest is the hypodynamic standstill. In this case the orchestra is completely silent. Nobody plays. In the heart, the sinus node does nothing and no heart muscle cell is excited.
These two forms of the Cardiac arrest are therefore treated slightly differently.
Possible causes of cardiac arrest
In order to stabilize the patient permanently, one has to find the cause of the cardiac arrest. This can be a heart bag tamponade, for example. Blood runs through a tear into the pericardium, as this cannot expand, after a short time there is so much blood in the bag that it creates enough pressure to prevent the heart from beating.
Another reason for cardiac arrest can be poisoning of all kinds. For example through drugs or medication. A heart attack or pulmonary embolism can also cause cardiac arrest.
A tension pneumothorax can also be the reason. Tension pneumothorax is a severe form of pneumothorax. In this case, through injury to the chest, air comes between the lungs and the lung membrane (Pleura). This causes the lungs to collapse because they are normally held against the inner chest wall by negative pressure. If there is a shock due to a serious accident with great blood loss, this may be one of the causes. Drowning, electrical accidents (these especially trigger ventricular fibrillation), severe hypothermia and heart failure can also trigger cardiac arrest.
All of these diseases are treated in the clinic after the circulation has been restored.
What are the signs / harbingers of cardiac arrest?
In many cases, cardiac arrest is preceded by a long-standing heart disease.
These include diseases such as coronary artery disease, heart failure or cardiac arrhythmias.
However, cardiac arrest often occurs without warning.
The direct signs of cardiac arrest are those affected suddenly passing out.
In doing so, they usually collapse and then react neither to speech nor to painful stimuli.
Since the heart has stopped beating, the pulse can no longer be felt.
Breathing stops after two minutes.
Signs of cardiac arrest can occur from a few minutes to even hours before the arrest.
These include angina pectoris symptoms (pain and pressure / tightness in the chest) as well as shortness of breath and sudden tiredness or faintness.
Fainting spells or dizziness can also be harbingers of cardiac arrest.
These complaints often arise in the context of physical exertion.
The load requires a significantly higher performance of the heart and can thus lead to cardiac arrest.
What are the risk factors for cardiac arrest?
Sudden cardiac arrest has many cardiac (coming from the heart) risk factors.
These include all types of heart disease: from previous heart attacks and cardiovascular arrests to cardiac insufficiency and cardiac arrhythmias to coronary heart disease and arteriosclerosis.
All of these diseases lead to a reduced performance of the heart and thus promote cardiac arrest.
The risk factors also include diseases that favor the development of heart disease.
These include metabolic diseases such as diabetes mellitus (diabetes) and hyperlipidemia (increase in cholesterol values = blood lipid values).
High blood pressure is also a risk factor for cardiac arrest.
In addition, smoking, increased alcohol consumption and an unhealthy lifestyle (little exercise, unbalanced high-fat diet) promote the development of heart disease and thus the occurrence of cardiac arrest.
Sudden cardiac arrest can also affect young people.
This usually occurs in the context of an inflammation of the heart muscle, as this disease acutely weakens the heart very severely.
Especially when the inflammation goes undetected and the person concerned is doing sport, the heart is overloaded and reacts with cardiac arrest.
You can read everything about myocarditis, the so-called myocarditis, in our article: Heart muscle inflammation - these are the symptoms and this is how the therapy takes place
Cardiac arrest in sleep
The risk of cardiac arrest while sleeping is particularly high in people with severe cardiac insufficiency.
While the blood follows gravity during the day when sitting or standing and partially sinks into the legs, it flows back to the heart during sleep due to the lying position.
This can overload the heart, which in turn can trigger cardiac arrest.
Another cause of cardiac arrest during sleep is what is known as sleep apnea.
It occurs mainly in people who snore and describes nocturnal breathing pauses.
These breathing pauses can last for several minutes, which leads to a lack of oxygen.
This lack of oxygen can have fatal effects on already weakened and / or overwhelmed heart cells.
They may stop working, leading to cardiac arrest.
Since a cardiac arrest is not always associated with pain, nobody notices anything about the arrest, especially at night.
As a result, the necessary rapid first aid cannot be provided, which is why death as a result of cardiac arrest is much more likely than during the day.
If you suffer from sleep apnea, read how to treat it: This is how sleep apnea is treated
What is reflex cardiac arrest?
The reflex cardiac arrest is triggered by excessive irritation of the vagus nerve.
The vagus nerve is the tenth cranial nerve and plays a key role in the regulation of many internal organs and thus also has an influence on the functioning of the heart.
In the event of excessive irritation, the vagus nerve regulates the heart function down to such an extent that cardiac arrest can occur.
Possible causes can be a blow to the solar plexus (e.g. in the pit of the stomach), a blow to the side of the neck or even immersion in very cold (<4 ° C) water.
So-called bolus death is also based on a reaction of the vagus nerve.
In this case, a foreign body that is too large (often not enough chewed food) gets stuck in the throat or accidentally gets into the windpipe.
This leads to irritation of the pharynx wall and thus to an excessive reaction of the vagus nerve.
Can you get cardiac arrest despite having a pacemaker?
A pacemaker is implanted in various heart diseases.
It is particularly valuable for diseases of the conduction system, as it can maintain a regular beating rhythm in the heart.
The pacemaker works as follows: The pacemaker can use a probe to measure the excitations given by the heart.
Based on its measurement results, the pacemaker produces weak currents that compensate for any failure of the sinus node (= natural pacemaker of the heart, center of excitation) and thus adapt the rhythm and keep it constant.
In the event of cardiac arrest, the pacemaker can detect that the heart is no longer excited.
In this case, the pacemaker stops working automatically.
Therefore, one can suffer cardiac arrest despite having a pacemaker.
Cardiac arrest during an operation
Cardiac arrest can occur as a complication during surgery.
As a rule, this affects people who already have one or more heart diseases, in which the heart is thus damaged.
Major operations are also associated with an increased risk of cardiac arrest.
In complex operations that are carried out on the heart, it may be necessary to induce an artificial cardiac arrest for a short time.
For this purpose, drugs are used that downregulate the heart's activity to a minimum.
Instead, the heart's function is taken over by a heart-lung machine that keeps the circulation intact.
This technique enables open heart surgery.
After completing the surgical measure, the medication is tapered so that the heart starts beating again on its own.
Why does a coma occur in cardiac arrest?
The heart is the pump for the human bloodstream.
Therefore, in the event of a cardiac arrest, the blood in the circulation also comes to a standstill.
The blood has a transport function in the body: it transports nutrients from the intestines and the liver to all organs; it is enriched with oxygen in the lungs in order to release it again in the organs.
It also transports the waste products that are produced by the metabolism in the organs to the liver and kidneys, where the products can be excreted.
In the event of cardiac arrest, this transport is interrupted.
This means that waste materials build up in the organs while the organs are not supplied with new nutrients or oxygen.
The brain, as one of our most important organs, is particularly dependent on a regular supply of oxygen.
After just a few seconds with no blood flow or oxygen, processes in the brain are regulated differently, so that affected people pass out.
If the insufficient supply of the brain continues, various cells in the brain die.
So that the brain does not use as much energy any more, it virtually switches to a state of rest.
The consciousness is switched off, so to speak, and a coma occurs.
What is resuscitation like in a cardiac arrest?
In the event of a sudden cardiac arrest, it is important to react quickly and initiate resuscitation measures in order to improve the person's chances of survival. In any case, the first aider must first ensure their own safety.
If a cardiac arrest is suspected, it must first be tested whether the person concerned reacts to speech or pain stimuli.
If this is not the case, breathing is checked.
If breathing has stopped, resuscitation should be started.
It is imperative that you call the emergency services BEFORE resuscitation (or have someone else call you).
Defibrillators are installed in many public buildings.
If available, this should be obtained.
The resuscitation itself consists of chest compressions and ventilation.
Ideally, resuscitation is performed by two people, so that one person performs 30 compressions of the chest (speed: 2 / second; location: in the middle of the chest, depth: approx. 1/3 of the chest, complete relief of the chest after each compression) and the other person makes two breaths.
These should always take place alternately (30: 2).
If a defibrillator is available, the electrodes are attached to analyze the heart rhythm.
The devices are understandable to laymen and indicate the necessary work steps.
The measures are carried out until the person concerned reacts.
Then the patient is positioned in a stable lateral position with regular breathing and consciousness checks.
Alternatively, resuscitation is continued until the emergency doctor arrives.
If several first aiders are available, they should take turns during the resuscitation, otherwise fatigue will quickly occur.
The procedure for resuscitation summarized:
Ideally, two people perform the resuscitation.
- first person: makes 30 chest compressions
→ Speed: 2 / second
Location: in the middle of the sternum
Depth: approx. 1/3 of the chest
→ Complete relief of the chest after every compression!
- second person: performs 2 breaths
→ alternately 30: 2
What are the chances of survival in a cardiac arrest?
The chances of survival after a cardiac arrest are generally classified as very low.
The survival rate is only about five percent.
However, the chance of survival can be significantly improved by first aiders.
On average, the chance of survival after a cardiac arrest decreases by about ten percent with every minute that passes.
Therefore, after ten minutes, the chances are about zero.
Normally, even if the ambulance is called at the same time as the cardiac arrest, it does not appear until after this ten-minute window, so that the chances of survival are in the hands of the first responder.
With the help of the resuscitation measures, not only can the heart beating again.
In addition, chest compressions and ventilation alone transport oxygen to the organs of the body, so that they can be protected from damage to a certain extent.
In this way, consequential damage from cardiac arrest can be minimized.
If a defibrillator is also used within the first few minutes of resuscitation, the person's chance of survival increases by up to 75 percent.
AEDs (automatic external defibrillators) are now available in many public buildings.
These explain the necessary work steps by themselves and are also suitable for use by medical laypeople.
If you want to know how to use an automated external defibrillator (AED) then check out our related article:
This is how an AED is used
What are the consequences / consequential damage of cardiac arrest?
The worst consequence of cardiac arrest is death.
The human body relies on a permanently functioning heart because it maintains the circulation.
Every minute, oxygen has to be pumped into the various organs along with other nutrients.
At the same time, it is necessary to remove the accumulating metabolic waste.
In cardiac arrest, the brain is one of the earliest organs affected.
The first damage to the brain becomes noticeable after just four minutes.
These are mainly due to the sudden lack of oxygen.
The brain cells die down and cause permanent damage.
But other organs can also be damaged.
In addition to the brain, the liver and kidneys in particular react very quickly to the lack of oxygen.
Here, too, cell death occurs, which in turn can cause irreversible damage.
The prognosis after a cardiac arrest depends on how long the resuscitation of the affected person takes.
The longer the organs are not supplied, the more severe the damage that occurs there.
Due to the insufficient supply of the brain, a temporary or permanent coma can occur.
When does brain damage start?
Brain damage occurs within a few minutes after a cardiovascular arrest.
The first damage to the brain becomes noticeable after just 4 minutes.
If the person concerned is resuscitated quickly, the damage may even regress completely.
The longer the cardiac arrest lasts, the worse the chances of a full recovery.
After eight to ten minutes, irreversible (= irreversible) damage occurs.
Resuscitation consisting of chest compressions and ventilation can maintain a certain amount of blood circulation so that the brain is still supplied with oxygen.
Even under these measures, brain damage occurs, but this occurs later than if no measures are taken.
