Cardiac Arrest
Disease Details
Family Health Simplified
- Description
- Cardiac arrest is a sudden loss of heart function, causing the heart to stop pumping blood effectively to the body and brain.
- Type
- Cardiac arrest is not a specific disease but a sudden loss of heart function. It can result from various underlying conditions, including genetic ones. Some genetic disorders that increase the risk of cardiac arrest, such as certain cardiomyopathies or channelopathies, can follow autosomal dominant or autosomal recessive patterns of genetic transmission.
- Signs And Symptoms
- Cardiac arrest is not preceded by any warning symptoms in approximately 50 percent of people. For individuals who do experience symptoms, the symptoms are usually nonspecific to the cardiac arrest. For example, new or worsening chest pain, fatigue, blackouts, dizziness, shortness of breath, weakness, or vomiting.When cardiac arrest is suspected by a layperson (due to signs of unconsciousness, abnormal breathing, and/or no pulse) it should be assumed that the victim is in cardiac arrest. Bystanders should call 911 or emergency medical services and initiate CPR.
- Prognosis
- The overall rate of survival among those who have OHCA is 10%. Among those who have an OHCA, 70% occur at home, and their survival rate is 6%. For those who have an in-hospital cardiac arrest (IHCA), the survival rate one year from at least the occurrence of cardiac arrest is estimated to be 13%. For IHCA, survival to discharge is around 22%. Those who survive to return of spontaneous circulation and hospital admission frequently present with post-cardiac arrest syndrome, which usually presents with neurological injury that can range from mild memory problems to coma. One-year survival is estimated to be higher in people with cardiac admission diagnoses (39%) when compared to those with non-cardiac admission diagnoses (11%).A 1997 review found rates of survival to discharge of 14%, although different studies varied from 0 to 28%. In those over the age of 70 who have a cardiac arrest while in hospital, survival to hospital discharge is less than 20%. How well these individuals manage after leaving the hospital is not clear.The global rate of people who were able to recover from OHCA after receiving CPR has been found to be approximately 30%, and the rate of survival to discharge from the hospital has been estimated at 9%. Survival to discharge from the hospital is more likely among people whose cardiac arrest was witnessed by a bystander or emergency medical services, who received bystander CPR, and who live in Europe and North America. Relatively lower survival to hospital discharge rates have been observed in Asian countries.Prognosis is typically assessed 72 hours or more after cardiac arrest. Rates of survival are better in those who had someone witness their collapse, received bystander CPR, and/or had either V-fib or V-tach when assessed. Survival among those with V-fib or V-tach is 15 to 23%. Women are more likely to survive cardiac arrest and leave the hospital than men. Hypoxic ischemic brain injury is a concerning outcome for people suffering a cardiac arrest. Most improvements in cognition occur during the first three months following cardiac arrest, with some individuals reporting improvement up to one year post-cardiac arrest. 50 – 70% of cardiac arrest survivors report fatigue as a symptom.
- Onset
- Cardiac arrest involves a sudden loss of heart function, leading to a cessation of effective blood circulation. The onset is typically abrupt and unexpected, often occurring without prior warning.
- Prevalence
- Cardiac arrest is a significant public health issue, with varying prevalence rates depending on the population studied and geographical location. In the United States, the annual incidence of out-of-hospital cardiac arrest is approximately 356,000 cases, with an overall survival rate of around 10%. In developed countries, the prevalence of sudden cardiac arrest ranges from 50 to 100 per 100,000 people annually. Prevalence rates are higher in older adults and populations with existing heart conditions.
- Epidemiology
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**Epidemiology of Cardiac Arrest:**
Cardiac arrest is a sudden loss of heart function, which can lead to death if not treated immediately. The epidemiology of cardiac arrest varies:
- **Incidence:** Approximately 350,000 out-of-hospital cardiac arrests (OHCA) occur annually in the United States.
- **Survival Rates:** Survival rates are generally low, with around 10% or less of OHCA victims surviving to hospital discharge.
- **Age and Gender:** Higher incidence in older adults. Men are 2-3 times more likely than women to experience cardiac arrest.
- **Geographic Variation:** Incidence and survival rates can vary significantly across different regions and countries, influenced by factors such as emergency response systems, public awareness, and healthcare infrastructure.
- **Risk Factors:** Common risk factors include coronary artery disease, prior heart attacks, heart failure, and arrhythmias, among others.
Understanding these epidemiological aspects is crucial for improving prevention, treatment, and survival outcomes of cardiac arrest. - Intractability
- Cardiac arrest, by itself, is not inherently intractable, but the outcome and response to treatment can vary widely depending on the circumstances. Immediate medical intervention, such as cardiopulmonary resuscitation (CPR) and defibrillation, can sometimes successfully restore normal heart rhythm and function. However, if these measures are not promptly applied or if the underlying cause is severe or untreatable, the condition can be fatal or result in severe outcomes.
- Disease Severity
- Cardiac arrest is extremely severe and life-threatening. It requires immediate medical intervention to prevent death or severe brain damage.
- Healthcare Professionals
- Disease Ontology ID - DOID:0060319
- Pathophysiology
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Pathophysiology of cardiac arrest:
Cardiac arrest occurs when the heart abruptly ceases to pump blood effectively, leading to a sudden loss of blood flow to the brain and other vital organs. The primary mechanisms include:
1. **Arrhythmias**: The most common cause is ventricular fibrillation (VF), where erratic electrical impulses cause quivering rather than coordinated contractions of the ventricles. Other arrhythmias can include ventricular tachycardia (VT), asystole, and pulseless electrical activity (PEA).
2. **Electrophysiological disruptions**: These disruptions affect the heart's electrical conduction system, resulting in the failure of the heart to produce adequate mechanical contractions.
3. **Myocardial ischemia or infarction**: Reduced blood flow or blockage in the coronary arteries can lead to heart muscle damage, impairing its ability to pump efficiently.
4. **Structural heart disease**: Conditions such as cardiomyopathy, valvular heart disease, or congenital heart defects can predispose individuals to cardiac arrest.
5. **Metabolic imbalances**: Electrolyte disturbances (e.g., hyperkalemia or hypokalemia), severe acidosis, hypoxia, or drug toxicity can trigger cardiac arrest. - Carrier Status
- Carrier status is not applicable to cardiac arrest. Cardiac arrest is a sudden loss of heart function, breathing, and consciousness usually caused by an electrical disturbance in the heart disrupting its pumping action. It is not a genetic condition that one can be a carrier of.
- Mechanism
- The definitive electrical mechanisms of cardiac arrest, which may arise from any of the functional, structural, or physiologic abnormalities mentioned above, are characterized by arrhythmias. Ventricular fibrillation and pulseless or sustained ventricular tachycardia are the most commonly recorded arrhythmias preceding cardiac arrest. These are rapid and erratic arrhythmias that alter the circulatory pathway such that adequate blood flow cannot be sustained and is inadequate to meet the body's needs.The mechanism responsible for the majority of sudden cardiac deaths is ventricular fibrillation. Ventricular fibrillation is a tachyarrhythmia characterized by turbulent electrical activity in the ventricular myocardium leading to a heart rate too disorganized and rapid to produce any meaningful cardiac output, thus resulting in insufficient perfusion of the brain and essential organs. Some of the electrophysiologic mechanisms underpinning ventricular fibrillations include ectopic automaticity, re-entry, and triggered activity. However, structural changes in the diseased heart as a result of inherited factors (mutations in ion-channel coding genes, for example) cannot explain the sudden onset of cardiac arrest.In ventricular tachycardia, the heart also beats faster than normal, which may prevent the heart chambers from properly filling with blood. Ventricular tachycardia is characterized by an altered QRS complex and a heart rate greater than 100 beats per minute. When V-tach is sustained (lasts for at least 30 seconds), inadequate blood flow to heart tissue can lead to cardiac arrest.Bradyarrhythmias occur following dissociation of spontaneous electrical conduction and the mechanical function of the heart resulting in pulseless electrical activity (PEA) or through complete absence of electrical activity of the heart resulting in asystole. Similar to the result of tachyarrhythmias, these conditions lead to an inability to sustain adequate blood flow as well, though in the case of bradyarrhythmias, the underlying cause is an absence of mechanical activity rather than rapid beats leading to disorganization.
- Treatment
-
Cardiac arrest requires immediate treatment. The key steps include:
1. **Cardiopulmonary Resuscitation (CPR)**: Perform chest compressions at a rate of 100-120 compressions per minute. Provide rescue breaths if trained.
2. **Defibrillation**: Use an Automated External Defibrillator (AED) as soon as available. Follow the device's instructions to deliver an electric shock to the heart.
3. **Advanced Care**: Once medical professionals arrive, they may administer medications like epinephrine, provide advanced airway management, and continue resuscitation efforts.
4. **Post-Resuscitation Care**: If a pulse is restored, the patient requires transport to a hospital for further evaluation and treatment, which may include cooling the body (therapeutic hypothermia) and treating the underlying cause.
Swift intervention significantly increases the chances of survival and favorable outcomes. - Compassionate Use Treatment
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Compassionate use treatment or off-label and experimental treatments for cardiac arrest generally aim to provide options when standard treatments have failed or are not available. Some of these treatments include:
1. **Therapeutic Hypothermia**: Also called targeted temperature management (TTM), this involves cooling the patient's body to improve survival and neurological outcomes after cardiac arrest. While increasingly used, it can still be considered off-label depending on the specific protocol used.
2. **Extracorporeal Membrane Oxygenation (ECMO)**: ECMO is a complex procedure that provides cardiac and respiratory support. It is often used as a last resort in cases of severe cardiac or respiratory failure.
3. **Experimental Drugs**: Drugs that are being tested in clinical trials for their efficacy in cardiac arrest, such as specific antiarrhythmics, vasopressors, or drugs to improve neurological outcomes post-resuscitation.
4. **Novel Resuscitation Devices**: Experimental devices or advanced mechanical CPR devices are used in certain clinical settings to improve the chances of returning spontaneous circulation.
5. **Gene and Stem Cell Therapy**: Research in this area is ongoing, aiming to repair and regenerate damaged heart tissue.
These treatments are often accessed through clinical trials or special compassionate use programs and should be administered under strict medical supervision. - Lifestyle Recommendations
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### Lifestyle Recommendations for Cardiac Arrest Prevention:
1. **Healthy Diet:**
- Consume a balanced diet rich in fruits, vegetables, whole grains, and lean proteins.
- Avoid trans fats, excessive salt, and added sugars.
- Incorporate heart-healthy fats such as those found in fish, nuts, and olive oil.
2. **Regular Exercise:**
- Aim for at least 150 minutes of moderate-intensity aerobic exercise or 75 minutes of vigorous-intensity exercise per week.
- Include muscle-strengthening activities on 2 or more days a week.
3. **Weight Management:**
- Maintain a healthy weight through diet and exercise.
- Monitor body mass index (BMI) and waist circumference.
4. **Quit Smoking:**
- Avoid both active smoking and exposure to secondhand smoke.
- Seek support programs or medications if needed to quit smoking.
5. **Limit Alcohol Consumption:**
- If you consume alcohol, do so in moderation—up to one drink per day for women and up to two drinks per day for men.
6. **Monitor Blood Pressure:**
- Regularly check your blood pressure.
- Follow medical advice to keep your blood pressure within a normal range.
7. **Control Cholesterol Levels:**
- Have regular cholesterol screenings.
- Use dietary changes, exercise, and medications if prescribed to maintain healthy cholesterol levels.
8. **Manage Diabetes:**
- Keep blood sugar levels under control through diet, exercise, and medications if needed.
- Regularly monitor blood glucose levels as advised by your healthcare provider.
9. **Reduce Stress:**
- Engage in relaxation techniques such as yoga, meditation, or deep-breathing exercises.
- Aim for a healthy work-life balance and seek professional counseling if needed.
10. **Regular Medical Checkups:**
- Have regular health screenings and checkups to monitor for potential cardiovascular risk factors.
- Follow your healthcare provider's recommendations for managing any existing health conditions.
Adapting these lifestyle changes can significantly lower the risk of cardiac arrest and improve overall heart health. - Medication
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Medications recommended in the ACLS protocol include epinephrine, amiodarone, and lidocaine. The timing and administration of these medications depends on the underlying arrhythmia of the arrest.
Epinephrine acts on the alpha-1 receptor, which in turn increases the blood flow that supplies the heart. Epinephrine in adults improves survival but does not appear to improve neurologically normal survival. In ventricular fibrillation and pulseless ventricular tachycardia, 1 mg of epinephrine is given every 3–5 minutes, following an initial round of CPR and defibrillation. Doses higher than 1 mg of epinephrine are not recommended for routine use in cardiac arrest. If the person has a non-shockable rhythm, such as asystole, following an initial round of CPR, 1 mg of epinephrine should be given every 3–5 minutes, with the goal of obtaining a shockable rhythm.Amiodarone and lidocaine are anti-arrhythmic medications. Amiodarone is a class III anti-arrhythmic. Amiodarone may be used in cases of ventricular fibrillation, pulseless ventricular tachycardia, and wide complex tachycardia. Lidocaine is a class Ib anti-arrhythmic, also used to manage acute arrhythmias. Anti-arrhythmic medications may be used after an unsuccessful defibrillation attempt. However, neither lidocaine nor amiodarone, in those who continue in ventricular tachycardia or ventricular fibrillation despite defibrillation, improves survival to hospital discharge, despite both equally improving survival to hospital admission. Following an additional round of CPR and defibrillation, amiodarone can also be administered. The first dose is given as a 300 mg bolus. The second dose is given as a 600 mg bolus. - Repurposable Drugs
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There are several existing drugs that have shown potential for repurposing in the treatment of cardiac arrest. These include:
1. **Amiodarone**: An antiarrhythmic agent that is sometimes used during cardiopulmonary resuscitation (CPR) to treat ventricular fibrillation or ventricular tachycardia that is unresponsive to defibrillation.
2. **Lidocaine**: Another antiarrhythmic drug that can be used as an alternative to amiodarone in the management of life-threatening ventricular arrhythmias.
3. **Epinephrine**: Commonly used during CPR to increase coronary and cerebral perfusion pressures, although there is ongoing debate about the overall impact on survival and neurological outcomes.
4. **Vasopressin**: Sometimes used as an alternative to epinephrine, particularly in cases of asystole or pulseless electrical activity.
5. **Beta-blockers (e.g., esmolol)**: There is some evidence supporting their use in refractory ventricular fibrillation to help stabilize the heart rhythm.
6. **Magnesium sulfate**: Used in specific scenarios such as torsades de pointes, a particular type of ventricular tachycardia.
Research is ongoing to better understand the full potential and efficacy of these and other drugs when repurposed for the treatment of cardiac arrest. - Metabolites
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Cardiac arrest is primarily a clinical condition involving the sudden cessation of heart function. During cardiac arrest, the lack of blood flow affects the metabolism of tissues and can lead to a buildup of certain metabolites. Key metabolites involved include:
1. **Lactate**: Levels significantly increase due to anaerobic metabolism when oxygen supply is inadequate.
2. **Potassium**: Elevated levels (hyperkalemia) can occur due to cell breakdown and impaired renal function.
3. **Glucose**: May vary; hyperglycemia or hypoglycemia can both occur due to stress response and impaired metabolic regulation.
4. **Carbon Dioxide (CO2)**: Increases due to impaired respiratory function and metabolic acidosis.
5. **pH Levels**: Metabolic acidosis is common, resulting in reduced pH levels due to the accumulation of lactate and CO2. - Nutraceuticals
- For cardiac arrest, nutraceuticals are not a primary treatment. Immediate medical intervention, such as CPR and defibrillation, is crucial. Nutraceuticals may play a role in overall heart health and prevention, but they are not suitable for acute management of cardiac arrest.
- Peptides
- Cardiac arrest is a sudden loss of heart function, leading to a cessation of blood circulation. Peptides involved in cardiac function and cardioprotection include natriuretic peptides like ANP and BNP, which are crucial for cardiovascular homeostasis. While there are no specific peptides universally acknowledged for treating or diagnosing cardiac arrest directly, ongoing research explores various peptides' roles in managing heart disease and potential therapeutic applications. If "nan" refers to nanotechnology, it's increasingly being investigated for its potential to deliver drugs, including peptides, more effectively in cardiac conditions. Nanoparticles may offer targeted drug delivery systems to improve survival and recovery outcomes following cardiac arrest.