What is Cardiac Arrest: Symptoms, and Causes of Cardiac Arrest Explained

Cardiac arrest is a life threatening medical emergency that strikes without warning, leaving little time for response. This guide delves into the intricate details of cardiac arrest, emphasizing the life-saving role of CPR training. Understanding what causes cardiac arrest, recognizing early signs, and knowing the correct response mean the difference between life and death.


What exactly is Cardiac Arrest?

Cardiac arrest is considered a type of heart diseases, in which the heart stops beating, preventing blood flow to the rest of the body. This abrupt cessation of heart function leads to a lack of oxygen in vital organs, including the brain, and results in serious consequences or death if not addressed promptly.

What causes cardiac arrest?

Cardiac arrest is caused by a variety of factors, encompassing both lifestyle-related choices and underlying medical conditions. Here are the primary causes of cardiac arrest:

  1. Coronary Artery Disease (CAD): The most common cause of cardiac arrest is coronary artery disease, where the blood vessels supplying the heart muscle become narrowed or blocked, reducing blood flow to the heart.
  2. Heart Attack: A heart attack triggers cardiac arrest. During a heart attack, blood flow to a part of the heart muscle is blocked, leading to damage and potential disruption of the heart's electrical system.
  3. Arrhythmias: Irregular heart rhythms like ventricular fibrillation, cause cardiac arrest. These abnormal heart rhythms disrupt the coordinated pumping action of the heart.
  4. Cardiomyopathy: This condition involves the deterioration of the heart muscle, affecting its ability to pump blood effectively and increasing the risk of cardiac arrest.
  5. Electrolyte Imbalance: Disturbances in the balance of electrolytes, such as potassium and sodium, affect the heart's electrical activity, potentially leading to cardiac arrest.

Young adults, specially athletes who experience cardiac arrest is caused by various factors including inherited heart conditions, structural heart defects, arrhythmias, drug use, hot tub exposure, severe blow to the chest, and certain medical conditions such as long QT syndrome and Brugada syndrome.

Causes of cardiac arrest in pregnant patients include complications such as hypertensive disorders, amniotic fluid embolism, cardiomyopathy, pulmonary embolism, and other conditions affecting cardiovascular health during pregnancy.

How does cardiac arrest differ from a heart attack?

Cardiac arrest is more dangerous than a heart attack because it involves the sudden cessation of the heart's pumping action, leading to immediate loss of consciousness and potential death within minutes if not treated promptly with CPR and defibrillation. In contrast, a heart attack involves a blockage in a coronary artery, which causes chest pain and damage to the heart muscle but does not result in immediate loss of life if medical treatment is sought promptly.

While related, heart attack and cardiac arrest have different causes, symptoms, and responses, emphasizing the importance of understanding the nuances for effective emergency intervention.

  • Underlying Cause: Cardiac arrest is primarily an electrical problem, while a heart attack is a circulation problem caused by a blocked artery.
  • Symptoms: Cardiac arrest typically occurs suddenly without warning. On the other hand, heart attack symptoms often develop more gradually, with chest discomfort, pain, shortness of breath, and other signs that intensify over time. 
  • Response: The immediate response to cardiac arrest involves CPR and defibrillation. For a heart attack, administering aspirin if appropriate, and considering interventions like angioplasty.

Are there specific risk factors that increase the likelihood of experiencing cardiac arrest?

Several factors increase the likelihood of experiencing cardiac arrest. Here are the following risk factors for cardiac arrest:

  • Smoking: Tobacco smoke contributes to atherosclerosis, increasing the risk of CAD.
  • Poor Diet: Diets high in saturated and trans fats lead to high cholesterol and atherosclerosis.
  • Lack of Exercise: Sedentary lifestyles contribute to obesity and cardiovascular problems.
  • Excessive Alcohol and Drug Use: Substance abuse, including alcohol and certain drugs, adversely affects the heart.
  • Age: The risk of cardiac arrest increases with age.
  • Gender: Men are generally at higher risk than premenopausal women; however, the risk equalizes post-menopause.
  • Family History: A family history of heart disease or sudden cardiac arrest increases the risk.
  • Previous Heart Conditions: Individuals with a history of heart attacks, heart failure, or arrhythmias are at elevated risk.
  • Diabetes: Diabetes is associated with an increased risk of CAD and other cardiovascular complications.


What are the early warning signs of cardiac arrest?

Cardiac arrest often occurs suddenly and without warning, and individuals may not experience any specific symptoms beforehand. However, some people exhibit signs that could suggest an increased risk of cardiac arrest or an underlying heart condition. These signs include:

  • Chest Discomfort: Some experience chest discomfort or pain, often described as pressure, tightness, or squeezing. This occurs intermittently or persistently.
  • Shortness of Breath: Unexplained breathlessness, especially when at rest or with minimal exertion, is a warning sign.
  • Dizziness or Lightheadedness: Feeling dizzy or lightheaded, particularly when standing up.
  • Fatigue: Persistent and unexplained fatigue, weakness, or a feeling of being unusually tired is a sign of an underlying heart issue.
  • Heart Palpitations: Irregular heartbeats or palpitations are symptoms, although they occur without warning.


Prompt recognition of cardiac arrest signs is crucial for better outcomes. If you witness these symptoms, call 911 and start CPR immediately if trained. Use an AED if available and continue CPR until help arrives. Early CPR and defibrillation improve survival chances.

Blood Pressure Category
Systolic (Upper)
Diastolic (Lower)
Health Risks
Less than 120 mm Hg
and Less than 80 mm Hg
Low risk of heart disease or stroke
Maintain healthy lifestyle (diet, exercise, no smoking)
120-129 mm Hg
and Less than 80 mm Hg
Doubled risk of cardiovascular complications
Make lifestyle changes (lose weight if overweight, increase physical activity, limit alcohol)
Hypertension Stage 1
130-139 mm Hg
or 80-89 mm Hg
Increased risk of heart attack, stroke, kidney disease
Lifestyle changes and potentially medication under doctor's guidance
Hypertension Stage 2
140 mm Hg or Higher
or 90 mm Hg or Higher
High risk; can lead to heart failure, vision loss, dementia
Medication required in addition to lifestyle changes as recommended by doctor
Hypertensive Crisis
Higher than 180 mm Hg
nd/or Higher than 120 mm Hg
Immediate danger of life-threatening complications
Seek emergency medical care immediately
Cardiac Arrest
Heart Attack
Sudden loss of heart function, leading to collapse
Blockage in a coronary artery, affecting blood flow to the heart muscle
Interruption of blood flow to the brain, leading to brain damage
Main Cause
Electrical malfunction of the heart
Blockage in coronary arteries
Blockage or rupture of blood vessels in the brain
Circulation Affected
Entire body
Heart muscle
Brain tissue
105Sudden collapse, unconsciousness, no pulse
Chest pain or discomfort, shortness of breath
Sudden numbness or weakness, confusion, trouble speaking or understanding speech/73
Emergency Response
Immediate CPR and defibrillation
Activate emergency medical services, chew aspirin
Activate emergency medical services, FAST assessment (Face, Arms, Speech, Time)
CPR, defibrillation
Thrombolytic therapy, angioplasty, stenting
Thrombolytic therapy, clot retrieval,
Long-term Management
Implantable cardioverter-defibrillator (ICD), medication management
Medication management, lifestyle changes, cardiac rehabilitation
Medication, rehabilitation, lifestyle changes
Dependent on prompt CPR and defibrillation, underlying health conditions
Dependent on extent of heart muscle damage, effectiveness of intervention
Dependent on severity of brain damage, rehabilitation progress
Risk Factors
Previous heart conditions, arrhythmias, electrolyte imbalances
Atherosclerosis, high cholesterol, hypertension, smoking, diabetes
Hypertension, diabetes, smoking, high cholesterol, atrial fibrillation

Treatments and ACLS Cardiac Arrest Algorithm

Once professional medical responders arrive, they will provide advanced life support, including advanced airway management, intravenous medications, and additional defibrillation if needed.

  • Hospital Care: The person will be transported to the hospital for further evaluation and treatment. In the hospital, medical professionals will conduct tests, such as coronary angiography, to identify and address the underlying cause, such as a blocked artery.
  • Therapeutic Hypothermia: In some cases, therapeutic hypothermia is employed to lower the body temperature, which has been shown to improve neurological outcomes after cardiac arrest.
  • Medications: Medications are administered to stabilize the heart rhythm, reduce the risk of blood clots, and manage other cardiac conditions.
  • Rehabilitation: Post-cardiac arrest care often involves rehabilitation to help the individual regain strength and functionality. This includes physical therapy, occupational therapy, and cardiac rehabilitation programs.
  • Monitoring and Follow-up: Continuous monitoring is essential to detect and manage any potential complications. Follow-up care is crucial for long-term recovery and to address any underlying cardiovascular issues that contributed to the cardiac arrest.

Magnesium is indicated in certain cases of cardiac arrest associated with specific arrhythmias such as torsades de pointes, which responds to magnesium sulfate administration.

What is P.E.A. Cardiac Arrest?

Pulseless Electrical Activity (PEA) cardiac arrest is a condition where the heart's electrical activity is present on the monitor, but there is no detectable pulse. In PEA, the heart's electrical system is functioning, but the mechanical pumping action is insufficient to generate a pulse and maintain effective circulation. It is a form of cardiac arrest that requires immediate intervention, including CPR and advanced cardiac life support measures, to restore circulation and improve the chances of survival. Identifying and addressing reversible causes of PEA is crucial for successful resuscitation efforts.


What are the coding and classification considerations for cardiac arrest in medical records?

Coding and classification considerations for cardiac arrest in medical records are crucial for accurate documentation, billing, and tracking of patient outcomes. The coding system commonly used for this purpose is the International Classification of Diseases, Tenth Revision (ICD-10). The primary code for cardiac arrest is I46, and additional codes provide further details about the cause, type, and circumstances of the event. Here are the ICD-10 Codes for Cardiac Arrest:

  • I46 - Cardiac Arrest: This code is the main identifier for cardiac arrest.
  • I46.9 - Cardiac Arrest, Unspecified: Used when the specific cause or type of cardiac arrest is not specified.
  • I46.0 - Sudden Cardiac Death, Unspecified: Applied when the cause of death is sudden cardiac arrest without further specification.
  • I46.1 - Sudden Cardiac Death, of Noncardiac Origin: Used when the cardiac arrest results from a non-cardiac cause.
  • I46.8 - Other Cardiac Arrest: Applied when the cause of cardiac arrest is specified, such as drug-induced or hypothermia-related cardiac arrest.
  • I46.9 - Cardiac Arrest, Unspecified: When the medical record does not provide sufficient information about the type or cause of cardiac arrest.


How do medical professionals use this coding to track and treat cardiac arrest?

Accurate coding and classification in medical records, particularly using ICD-10 codes, are essential for effective patient care, billing accuracy, research endeavors, and quality improvement initiatives related to cardiac arrest. This standardized system enables healthcare professionals to track and treat cardiac arrest cases systematically, improving patient outcomes and overall healthcare quality.

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Blood Pressure Chart by Age

Age Group
Min Systolic/Diastolic
Normal Range
Max Systolic/Diastolic
1-12 months
Consult pediatrician if outside normal range. Cuff sizing is critical.
1-5 years
High BP in children may indicate underlying condition. Lifestyle factors.
6-13 years
Obesity, family history increase risk. Promote healthy habits early.
14-19 years
Adolescent rise normal. Rule out secondary causes if elevated.
20-24 years
Stressors, medications may impact. Start monitoring if high-normal.
25-29 years
Dietary changes, exercise for elevated readings. Birth control effects.
30-39 years
110/77 - 111/78
122/81 - 123/82
134/85 - 135/86
Monitor closely if readings increasing with age.
40-49 years
112/79 - 115/80
125/83 - 127/84
137/87 - 139/88
Lifestyle changes proven to reduce hypertension risk.
50-64 years
116/81 - 121/83
129/85 - 134/87
142/89 - 147/91
White coat effect common. Home monitoring advised.
65+ years
130+ Systolic Risk
Frailty, medications, conditions factored in management.

Prognosis and Survival Rates Post Cardiac Arrest

According to study, the current overall survival rate of patients admitted to a hospital is approximately 10%, making cardiac arrest one of the leading causes of death in the United States. The situation is improving with the incorporation of therapeutic temperature modulation, aggressive prevention of secondary brain injury, and improved access to advanced cardiovascular support, all of which have decreased mortality and allowed for better outcomes.

How effective are current ACLS protocols in improving cardiac arrest survival rates?

Current Advanced Cardiovascular Life Support (ACLS) protocols have demonstrated effectiveness in improving cardiac arrest survival rates. These protocols emphasize early intervention with CPR, prompt defibrillation, and the administration of advanced cardiac medications.

The emphasis on high-quality CPR, rapid defibrillation in shockable rhythms, and integrated post-cardiac arrest care, including therapeutic hypothermia, have contributed to improved outcomes. Continuous quality improvement initiatives, training, and advancements in medical understanding further enhance the efficacy of ACLS protocols. 

Is cardiac arrest painful?

Cardiac arrest itself is not painful because consciousness is usually lost rapidly due to the lack of blood flow to the brain. Prior to cardiac arrest, individuals experiences discomfort such as chest pain, shortness of breath, palpitations, dizziness, or lightheadedness, depending on the underlying cause.

How many cardiac arrests can a person survive?

The number of cardiac arrests can a person survive varies and depends on factors such as the underlying cause of the arrest, the quality and timeliness of intervention, and the individual's overall health and medical history. A recent study on Survival after multiple episodes of cardiac arrest explained that surviving multiple cardiac arrests within a short period is less likely, with the study showing significantly higher in-hospital mortality rates for patients who had more than one CPR event in a 24-hour period compared to those who had CPR just once.

Can someone recover fully after a cardiac arrest?

Yes, survival from cardiac arrest is possible with immediate and effective intervention, including CPR, defibrillation, and prompt medical treatment. The potential for a full recovery after cardiac arrest depends on factors like prompt intervention, the underlying cause of the arrest, and the quality of post-arrest care. Ongoing medical support and emotional care contribute to the overall recovery process. Recovery from cardiac arrest varies depending on factors such as the individual's overall health, the cause of arrest, the quality of CPR and defibrillation provided, and any resulting neurological damage. Rehabilitation and ongoing medical care are necessary for optimal recovery. In some cases, athletes who experience cardiac arrest were able to return to sports after undergoing thorough cardiac evaluation and receiving clearance from their healthcare team.

Rehabilitation programs, psychosocial support, and ongoing cardiovascular management are crucial for enhancing overall well-being. While survival rates have improved, a personalized care plan is essential for optimizing outcomes and fostering a fulfilling life post-cardiac arrest.


How to Avoid Cardiac Arrest?

Avoiding cardiac arrest involves adopting a heart-healthy lifestyle, managing risk factors, and being aware of potential warning signs. Here are key measures to reduce the risk of cardiac arrest:

  1. Regular Health Check-ups: Schedule regular check-ups with your healthcare provider to monitor and manage conditions such as high blood pressure, high cholesterol, and diabetes.
  2. Healthy Diet: Adopt a balanced and heart-healthy diet that includes fruits, vegetables, whole grains, lean proteins, and limited saturated fats, trans fats, and sodium.
  3. Regular Exercise: Engage in regular physical activity. Aim for at least 150 minutes of moderate-intensity exercise per week or 75 minutes of vigorous-intensity exercise.
  4. Maintain a Healthy Weight: Achieve and maintain a healthy weight to reduce the risk of heart disease. Consult with a healthcare professional for guidance on weight management.
  5. Quit Smoking: If you smoke, quit. Smoking is a risk factor for heart disease and cardiac arrest. Seek support and resources to help you quit.
  6. Limit Alcohol Intake: If you drink alcohol, do so in moderation. Excessive alcohol consumption contributes to heart problems.
  7. Manage Stress: Adopt stress-reducing techniques, such as meditation, deep breathing exercises, or regular physical activity, to manage stress and promote heart health.
  8. Stay Hydrated: Maintain proper hydration by drinking an adequate amount of water. Dehydration strains the heart.
  9. Screen and Manage Heart Conditions: Identify and manage conditions such as atrial fibrillation, coronary artery disease, and heart failure as they contribute to the risk of cardiac arrest.
  10. Undergo Regular Health Screenings: Regular screenings for conditions like diabetes, high blood pressure, and high cholesterol help identify and manage risk factors before they lead to more serious issues.

What role does CPR training play in improving outcomes for cardiac arrest victims?

CPR training is pivotal for improving outcomes in cardiac arrest situations. Trained individuals facilitate early intervention by promptly initiating chest compressions, minimizing delays, and sustaining vital organ circulation. This sustains blood oxygenation, buying crucial time for advanced medical interventions. Studies consistently show increased survival rates with immediate CPR, which is a bridge to defibrillation and enhances AED utilization.

Empowering bystanders through community readiness and participation in public access defibrillation programs further amplifies the impact of CPR training. Beyond immediate benefits, CPR contributes to reducing long-term complications, offering neurological benefits, and improving post-cardiac arrest care. Widespread CPR training creates a culture of preparedness, fostering community resilience by increasing the likelihood of timely assistance during cardiac emergencies.