Cardiac arrest is the sudden loss of blood flow from heart failure to pump effectively. Symptoms include loss of consciousness and abnormal or absent respiration. Some individuals may experience chest pain, shortness of breath, or nausea before a heart attack. If left untreated within minutes, it usually causes death.
The most common cause of cardiac arrest is coronary artery disease. Less common causes include loss of blood, lack of oxygen, very low potassium, heart failure, and intense physical exercise. A number of congenital abnormalities may also increase the risk including long QT syndrome. Early heart rhythm is the most common ventricular fibrillation. Diagnosis is confirmed by not finding the pulse. While heart attacks can be caused by heart attacks or heart failure, this is not the same.
Prevention includes not smoking, physical activity, and maintaining a healthy weight. Treatment for cardiac arrest includes direct cardiopulmonary resuscitation (CPR) and, if there is a surprising rhythm, defibrillation. Among those who survive, targeted temperature management can improve yield. Implanted heart defibrillators may be placed to reduce the likelihood of death from recurrence.
In the United States, cardiac arrest outside the hospital occurs in about 13 per 10,000 people per year (326,000 cases). At the hospital a heart attack occurred in an additional 209,000. Heart arrest is becoming more common with age. It affects men more often than women. The percentage of people who survive on treatment is about 8%. Many who survive have significant disabilities. Many US television shows, however, have described an unrealistic high survival rate of 67%.
Video Cardiac arrest
Signs and symptoms
Heart arrest was preceded by no warning symptoms in about 50 percent of people. For those who experience symptoms, they will be nonspecific, such as new or worsening chest pain, tiredness, fainting, dizziness, shortness of breath, weakness and vomiting. When a heart attack occurs, the most obvious sign of the event is the lack of a palpable pulse in the victim. Also, as a result of the loss of cerebral perfusion (blood flow to the brain), the victim will quickly lose consciousness and will stop breathing. The main criteria for diagnosing cardiac arrest, not respiratory arrest, which has many of the same features, is a lack of circulation; However, there are a number of ways to determine this. Near-death experiences are reported by 10 to 20 percent of people who survived a heart attack.
Certain types of quick interventions can often reverse heart attacks, but without such intervention, death is certain. In certain cases, a heart attack is the expected outcome of a serious illness in which death is thought to occur.
Maps Cardiac arrest
Cause
Sudden cardiac arrest (SCA) and sudden cardiac death (SCD) occur when the heart suddenly begins to beat with an abnormal or irregular rhythm (arrhythmia). Without organized electrical activity in the heart muscle, there is no consistent ventricular contraction, resulting in the inability of the heart to produce adequate heart output (pumping blood from the heart to the rest of the body). There are many different types of arrhythmias, but the most frequently noted in SCA and SCD are ventricular tachycardia (VT) or ventricular fibrillation (VF).
Sudden cardiac arrest can occur due to heart and non-cardiac causes including the following:
Coronary artery disease
Coronary artery disease (CAD), also known as ischemic heart disease, is responsible for 62 to 70 percent of all SCDs. CAD is a much less common cause of SCD in people under 40 years of age.
The case has shown that the most common finding on postmortem sudden cardiac death (SCD) examination is a chronic high-grade stenosis of at least one segment of the main coronary artery, the artery supplying the heart muscle with its blood supply.
Structural heart disease is not associated with CAD (ie, hypertrophic cardiomyopathy, congenital coronary artery anomaly, myocarditis) accounted for 10% of all SCDs. Examples include: cardiomyopathy, heart rhythm disturbances, myocarditis, hypertensive heart disease, and congestive heart failure.
Left ventricular hypertrophy is considered a major cause of SCD in adult populations. This most often is the result of long-standing high blood pressure that has caused secondary damage to the main chamber wall wall of the heart, the left ventricle.
A 1999 SCD review in the United States found that this accounts for more than 30% of SCDs for those under the age of 30. A study of military recruitment ages 18-35 found that this accounts for more than 40% of SCD.
Congestive heart failure increases the risk of SCD fivefold.
Arrhythmias
Arrhythmias are not due to structural heart disease that causes 5 to 10% of SCD.
Examples of arrhythmic syndromes associated with SCD include: Long QT Syndrome, Wolff-Parkinson-White Syndrome, Brugada Syndrome, polycorphic ventricle catecholics.
Long QT syndrome, a condition often mentioned in youth deaths, occurs in one in every 5000 to 7000 newborns and is estimated to be responsible for 3000 deaths each year compared to about 300,000 heart attacks seen by emergency services. This condition is a fraction of the overall death associated with a heart attack, but is a condition that may be detected prior to arrest and can be treated.
Non-cardiac causes
SCA because non-cardiac causes account for the remaining 15 to 25%.
The most common non-cardiac causes are trauma, hemorrhage (such as gastrointestinal bleeding, aortic rupture, or intracranial hemorrhage), overdose, drowning and pulmonary embolism. Cardiac arrest can also be caused by poisoning (for example, by the sting of a particular jellyfish).
Mnemonic for reversible causes
"Hs and Ts" is the name for mnemonic used to help remember the possible causes of a treatable or reversible heart attack.
- Hs
- H ypovolemia - Lack of blood volume
- H ypoxia - Lack of oxygen
- H ydrogen ions (Acidosis) - abnormal pH in the body
- H hepcalemia or H ypokalemia - Excess and inadequate potassium content can be life-threatening.
- H ypothermia - Low core body temperature
- H ypoglycemia or H glyglycemia - Low or high blood sugar
- Ts
- T ablet or T oxins
- Cardiac T amponade - Build fluid around the heart
- T ension pneumothorax - A collapsed lung
- T hrombosis (Myocardial infarction) - Heart attack
- T hromboembolism (Pulmonary embolism) - Blood clot in the lungs
- T raumatic cardiac arrest
Risk factors
Risk factors for SCD are similar to coronary artery disease and include age, smoking, high blood pressure, high cholesterol, lack of physical exercise, obesity, diabetes, and family history. Early episodes of sudden cardiac arrest also increase the risk of future episodes.
Current smokers with coronary artery disease have found an increase of two to three times the risk of sudden death between the ages of 30 and 59. In addition, it was found that the risk of former smokers closer to those who never smoked.
Mechanism
The mechanism of death in the majority of people who die of sudden cardiac death is ventricular fibrillation. Structural changes to the sick heart as a result of inherited factors (mutations in ion-channel channeling genes for example) can not explain suddenly SCD. Also, sudden cardiac death can be a consequence of electrical-mechanical dysfunction and bracharhythmias.
Diagnosis
Cardiac arrest is synonymous with clinical death. Cardiac arrest is usually diagnosed clinically by the absence of a pulse. In many cases, the lack of a carotid pulse is a gold standard for diagnosing cardiac arrest, as lack of pulse (especially peripheral pulse) can result from other conditions (eg shock), or simply a rescue error. Nevertheless, research shows that rescuers often make mistakes when checking carotid pulse in an emergency, whether they are health professionals or lay people.
Due to inaccuracies in this method of diagnosis, some bodies such as the European Resuscitation Council (ERC) have not emphasized the importance. The Resuscitation Council (UK), in line with the ERC's recommendations and those of the American Heart Association, has suggested that this technique should be used only by health care professionals with specialized training and expertise, and even then it should be viewed along with other indicators such as agonal respiration.
Various other methods of detecting circulation have been proposed. The guidelines after the 2000 International Liaison Committee on Resuscitation (ILCOR) recommendation are for saviors to look for "signs of circulation", but not specifically pulse rate. These signs include coughing, panting, color, twitching and movement. However, in the face of evidence that these guidelines are ineffective, the current ILCOR recommendation is that cardiac arrest should be diagnosed in all casual and non-breathing victims normally. Another method is to use a molecular autopsy or postmortem molecular testing that uses a series of molecular techniques to discover the ion channels damaged by the heart.
Classification
Doctors classify heart attacks as "shockable" versus "non-shockable", as determined by the ECG rhythm. This refers to whether a particular class of dysrhythmia of the heart can be treated using defibrillation. Two "shockable" rhythms are ventricular fibrillation and pulseless ventricular tachycardia while two "not easily electrocycled" rhythms are asystole and pulseless electrical activity.
Prevention
With positive results after a heart attack is not possible, efforts have been spent in finding effective strategies to prevent heart attacks. With the leading cause of cardiac arrest is ischemic heart disease, attempts to promote a healthy diet, exercise, and quitting smoking are important. For people at risk for heart disease, measures such as blood pressure control, cholesterol-lowering, and other medico-therapeutic interventions are used. A Cochrane review published in 2016 found medium-quality evidence to show that blood pressure-lowering drugs do not show up to reduce sudden cardiac death.
Team code
In medical language, cardiac arrest is referred to as "code" or "collision". This usually refers to the "blue code" in the hospital emergency code. The dramatic decrease in measurement of vital signs is referred to as "coding" or "crashing", although encoding is usually used when generating cardiac arrest, while perhaps not crashing. Treatment for heart attacks is sometimes referred to as "calling code".
People in public wards often deteriorate for several hours or even days before a heart attack occurs. This has been linked to a lack of knowledge and skills amongst environment-based staff, in particular failure to measure respiratory rate, which is often a major predictor of damage and often can change up to 48 hours before heart failure. In response to this, many hospitals have now increased training for environment-based staff. A number of "early warning" systems also exist that aim to measure the risk of people experiencing deterioration based on their vital signs and thus provide guidance to staff. In addition, specialist staff are used more effectively to supplement the work already done at the environmental level. These include:
- The Crash Team (or code team) - This is a designated staff member with special expertise in resuscitation called to place all hospital arrests. This usually involves a special equipment wagon (including a defibrillator) and drugs called "accident trolleys" or "crash trolleys".
- Medical emergency teams - These teams respond to all emergencies, with the aim of treating people in the acute phase of their illness to prevent heart attacks. These teams have been found to lower heart attack rates and improve survival.
- Critical care outreach - As well as providing services from two other types of teams, these teams are also responsible for educating non-specialist staff. In addition, they help facilitate the transfer between intensive care/high dependency units and general hospital wards. This is very important, as many studies have shown that a significant percentage of patients who are out of critical care environments are rapidly deteriorating and being treated again; outreach teams offer support to environmental staff to prevent this from happening.
Implantable cardioverter defibrillator
An implantable cardioverter defibrillator (ICD) is a battery-powered device that monitors electrical activity in the heart and when arrhythmias or detectable asysts are capable of giving an electric shock to end an abnormal rhythm. ICDs are used to prevent sudden cardiac death (SCD) in those who have survived the early episodes of sudden cardiac arrest (SCA) due to ventricular fibrillation or ventricular tachycardia (secondary prevention). ICDs are also used prophylactically to prevent sudden cardiac death in certain high-risk patient populations (primary prevention).
A number of studies have been conducted on the use of ICD for secondary prevention of SCD. These studies have shown increased survival with ICD compared with the use of antiarrhythmic drugs. ICD therapy is associated with a 50% relative risk reduction in deaths caused by arrhythmias and 25% relative risk reduction in all causes of death.
Primary prevention of SCD with ICD therapy for high-risk patient populations also similarly shows improved survival rates in a number of large studies. The population of high-risk patients in the study was defined as those with severe ischemic cardiomyopathy (determined by a reduced left ventricular ejection fraction (LVEF)). The LVEF criteria used in this trial range from less than or equal to 30% in MADIT-II to less than or equal to 40% in MUSTT.
Diet
Omega-3-derived unsaturated fatty acid (PUFA) has been promoted for the prevention of sudden cardiac death due to its postulated ability to lower triglyceride levels, prevent arrhythmias, decrease platelet aggregation, and lower blood pressure. However, according to a recent systematic review, supplementation of omega-3 PUFAs was not associated with a lower risk of sudden cardiac death.
Management
Sudden heart attacks can be treated through resuscitation efforts. This is usually done on the basis of basic life support (BLS)/advanced heart life support (ACLS), pediatric advanced life support (PALS) or guidelines for neonatal resuscitation (NRP) programs.
Cardiopulmonary Resuscitation
Cardiopulmonary resuscitation (CPR) is an important part of heart attack management. It is recommended that it start as soon as possible and be interrupted as little as possible. The CPR component that seems to make the biggest difference in most cases is chest compression. CPR done right, has been shown to improve survival; however, this was done in less than 30% of out-of-hospital arrests in 2007. If high-quality CPR does not result in the return of spontaneous circulation and a person's heart rhythm in asistol, stop CPR and say the person's death is fair after 20 minutes. Exceptions to this include people with hypothermia or who have drowned. Longer duration of CPR may make sense to those who have a heart attack while in hospital. CPR Bystander, by ordinary people, prior to the arrival of the EMS also improved results.
Neither a bag or valve mask can be used to help breathing. High oxygen levels are generally given during CPR. Tracheal intubation has not been found to improve survival rates in heart attacks and in prehospital environments may aggravate it. When performed by EMS 30 compression followed by two breaths appears better than continuous chest compressions and breath is given when compression is in progress.
For observers, CPR that only involves chest compression produces better results than the standard CPR for those who have experienced cardiac arrest due to heart problems. Mechanical chest compression (as the machine does) is no better than chest compression done by hand. It is unclear whether a few minutes of CPR before defibrillation produces different results from the immediate defibrillation. If cardiac arrest occurs after 20 weeks of pregnancy, a person should pull or push the uterus to the left during CPR. If the pulse has not returned by four minutes emergency caesarean section is recommended.
Defibrillation
Defibrillation is indicated if a shockable rhythm is present. Two remarkable rhythms are ventricular fibrillation and pulseless ventricular tachycardia. In children 2-4 J/Kg is recommended.
In addition, there is an increased use of public access defibrillation. This involves placing an automated external defibrillator in public places, and training staff in these areas how to use it. This allows defibrillation to occur before the arrival of emergency services, and has been shown to increase the chances of survival. Some defibrillators even provide feedback on the quality of CPR compression, encouraging the layman to squeeze one's chest hard enough to circulate blood. In addition, it has been shown that those who have arrests in remote locations have worse outcomes after a heart attack.
Drugs
By 2016, drugs, included in the guidelines, have not been shown to improve survival to return from hospital after a heart attack outside the hospital. These include the use of epinephrine (adrenaline), atropine, lidocaine, and amiodarone. Epinephrine is generally recommended every five minutes. Vasopressin as a whole does not increase or worsen the results compared with epinephrine. The combination of epinephrine, vasopressin, and methylprednisolone appears to improve yield.
Epinephrine appears to improve short-term outcomes such as the return of spontaneous circulation. Some of the shortcomings of long-term benefits may be related to delays in the use of epinephrine. While the evidence does not support its use in children, the guidelines state its use makes sense. Lidocaine and amiodarone are also considered fair in children with heart attacks that have a surprising rhythm. Common use of sodium bicarbonate or calcium is not recommended.
The 2010 Guidelines of the American Heart Association no longer contains recommendations for using atropine in electrical activity and a heartbeat because of a lack of evidence for its use. Both lidocaine and amiodarone, in those who continue with ventricular tachycardia or ventricular fibrillation despite defibrillation, improve survival to return to hospital but both increase survival for admission to the hospital.
Thrombolytics when used generally can cause harm but may be beneficial in those with pulmonary embolism confirmed as the cause of arrest. The evidence for the use of naloxone in those with heart attacks due to opioids is unclear but still usable. In those who have a heart attack due to local anesthesia, a lipid emulsion may be used.
Targeted temperature management
Adult cooling after cardiac arrest has a return of spontaneous circulation (ROSC) but no consciousness returns improved yield. This procedure is called targeted temperature management (formerly known as therapeutic hypothermia). People are usually cooled for 24 hours, with a target temperature of 32-36Ã, Â ° C (90-97Ã, Â ° F). There are a number of methods used to lower body temperature, such as applying ice packs or cold water circulation pads directly to the body, or implanting cold saline. This is followed by a gradual rewarming over the next 12 to 24 hours.
Recent meta- analysis has found that the use of therapeutic hypothermia after cardiac arrest outside the hospital is associated with improved survival rates and better neurologic outcomes.
Do not resuscitate
Some people choose to avoid aggressive actions at the end of life. A do not order resuscitation (DNR) in the form of previous health care directives make it clear that in the event of a heart attack, the person does not want to receive cardiopulmonary resuscitation. Other directives may be made to establish a desire for intubation in case of respiratory failure or, if convenience measures are all desirable, stipulating that the health care provider should "enable natural death".
Chain of survival
Some organizations promote the idea of ​​a survival chain. The chain consists of the following "links":
- Early recognition - If possible, the recognition of the disease before the person develops a heart attack will allow the savior to prevent the occurrence. Early recognition that a heart attack has occurred is the key to survival - because every minute a patient remains in a heart attack, their chances of survival fall by about 10%.
- Early CPR - improves blood flow and oxygen to vital organs, an essential component for treating heart attacks. In particular, by keeping the brain supplied with oxygenated blood, the likelihood of neurological damage decreases.
- Early defibrillation - effective for ventricular fibrillation management and pulseless ventricular tachycardia
- Advanced follow-up care
- Early post-resuscitation treatments that may include percutaneous coronary intervention
If one or more chain links are lost or delayed, the likelihood of survival decreases significantly.
These protocols are often initiated by blue codes, which usually indicate the onset of the coming or acute from a heart attack or respiratory failure, although in practice, the blue code is often referred to in less life-threatening situations that require immediate attention from the doctor.
More
Resuscitation with an extracorporeal membrane oxygenation device has been tried with better results for cardiac arrest in hospital (29% survival) than cardiac arrest outside the hospital (4% survival) in selected populations for the greatest benefit. Cardiac catheterization in those who survived cardiac arrest outside the hospital appears to improve results despite evidence of high quality is lacking. It is recommended that it be done as soon as possible in those who have had a heart attack with ST elevation due to underlying cardiac problems.
Precordial stacks may be considered in patients with unattended, monitored, unstable ventilatorel tachycardia (including VT pulseless) if the defibrillator is not immediately ready for use, but should not delay CPR and delivery of shock or be used on the unconscious out of the capture hospital.
Prognosis
The chance of overall survival among those who had a heart attack outside the hospital was 10%. Among those who had heart attacks outside the hospital, 70% occurred at home and their survival rate was 6%. For those who have a heart attack in the hospital, the survival rate is estimated at 24%. Among children's survival rates are 3 to 16% in North America. For the survival of a hospital heart attack to discharge about 22% with many having good neurological outcomes.
The prognosis is usually assessed 72 hours or more after a heart attack. Survival rates are better for those who see a collapse, get CPR by the patient, or have ventricular tachycardia or ventricular fibrillation when assessed. Survival between them with Vfib or Vtach is 15 to 23%. Women are more likely to survive a heart attack and leave the hospital than men.
A 1997 review found survival rates to be out of 14% although different studies varied from 0 to 28%. In those over 70 years who had a heart attack while in hospital, the survival to return to the hospital was less than 20%. How well these people are able to manage after leaving the hospital is not clear.
A study of survival rates from heart attacks outside the hospital found that 14.6% of those who had received resuscitation by ambulance staff survived as far as admission to the hospital. Of these, 59% died while entering, half of this in the first 24 hours, while 46% survived to get out of the hospital. This reflects overall survival after heart attack by 6.8%. Of these 89% had normal brain function or mild neurological defects, 8.5% had moderate disturbance, and 2% had major neurological disorders. Of those who leave the hospital, 70% are alive four years later.
Epidemiology
Based on death certificates, sudden cardiac death accounts for about 15% of all deaths in Western countries. In the United States, 326,000 cases outside the hospital and 209,000 hospital cases occur heart attacks among adults a year. The lifetime risk was three times greater in men (12.3%) than women (4.2%) based on the Framingham Heart Study analysis. But this gender difference disappears beyond the age of 85.
In the United States during pregnancy, heart attacks occur in about one in twelve thousand births or 1.8 per 10,000 live births. Rates are lower in Canada.
Society and culture
Name
In many publications the declared or implicit meaning of "sudden cardiac death" is a sudden death from a cardiac cause. However, doctors sometimes call a heart attack "sudden cardiac death" even if the person survives. Thus one can hear the term "early episode of sudden cardiac death" in a living person.
In 2006, the American Heart Association presented the definition of sudden cardiac arrest and sudden cardiac death as follows: "Cardiac arrest is a sudden cessation of heart activity so that the victim becomes unresponsive, without normal breathing and no signs of circulation.If the corrective action is not taken rapidly, this condition develops into sudden death Cardiac arrest should be used to indicate an event as described above, which is reversed, usually with CPR and/or defibrillation or cardioversion, or a pacemaker Sudden cardiac death should not be used to describe events which is not fatal ".
Show code
In some medical facilities, the resuscitation team can deliberately respond gradually to a person in a heart attack, a practice known as "slow code", or perhaps falsify responses altogether for the family's sake, a practice known as "event code ". This is generally done for people who do CPR will not have any medical benefits. Such practices are ethically controversial, and are prohibited in some jurisdictions.
References
External links
- Resuscitation Science Center at University of Pennsylvania Hospital
Source of the article : Wikipedia
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