Understanding Sudden Cardiac Arrest : Causes, Prevention, and Treatment

1. Introduction

   1. What is Sudden Cardiac Arrest?

      Sudden cardiac arrest is known to be a life-threatening condition in which the heart suddenly stops beating. It is not a heart attack but can be related.⁽¹⁾ It occurs when there is a malfunction of the electrical system of the heart. This causes an abnormal rhythm called ventricular rhythm. This prevents the heart from effectively pumping blood to the rest of the body.

      A study shows around half of all cardiovascular deaths in the United States result from sudden cardiac arrest.⁽²⁾

      During sudden cardiac arrest, the blood flow to the heart is severely reduced. If medical intervention is not received there is loss of consciousness, cessation of breathing, and even death.

   2. Impact of Sudden Cardiac Arrest on Individuals and Society

      Sudden cardiac arrest can have a significant impact on the individual and society due to the following reasons: 

      • It is a life-threatening medical emergency and if not treated promptly can result in death. Immediate attention is important for increasing the chances of survival.
      • Sudden cardiac arrest has a high fatality rate. If immediate cardiopulmonary resuscitation and defibrillation are not received the survival rate decreases.
      • Sudden cardiac arrest has a devastating effect on the individual and families. It comes over without any warning and affects individuals of all ages. The abrupt loss of consciousness can have an impact on the person experiencing sudden cardiac arrest and the loved ones.
      • There can be a sudden economic burden on the society as well. The impact of lost productivity and potential disability further exacerbates the economic burden.

       Sudden cardiac arrest is a critical health issue with far-reaching complications. It can affect families, communities, and society as a whole.

      Early recognition, immediate intervention, public awareness, and ongoing research can be helpful in tackling this life-threatening condition and improving the outcome.

2. Causes and Risk Factors of Sudden Cardiac Arrest

   There are several causes and risk factors that cause sudden cardiac arrest.^(3, 4)

   Underlying Heart Conditions: Most cases of sudden cardiac arrest may be due to underlying heart conditions which may include:

   • Coronary Artery Disease: A condition in which the arteries supplying blood to the heart become narrowed or blocked due to atherosclerosis. This restricts the blood flow and oxygen to the heart muscles and increases the risk of abnormal heart rhythm.
   • Arrhythmia: Abnormal heart rhythm can trigger sudden cardiac arrest.
   • Structural Heart Abnormalities: Heart abnormalities such as hypertrophic cardiomyopathy, dilated cardiomyopathy, and congenital heart defects, increase the risk of sudden cardiac arrest.
   • Genetic factors and Family History: Certain inherited conditions such as long QT syndrome, Brugada syndrome, or catecholaminergic polymorphic ventricular tachycardia can predispose people to abnormal heart rhythms and sudden cardiac events.

   Lifestyle Factors: Certain lifestyle factors can increase the risk of sudden cardiac arrest. These include:

   • Poor diet
   • Smoking
   • Sedentary lifestyle
   • Substance abuse

   Age, Gender, and Race: As age increases the risk of sudden cardiac arrest increases.

    The above factors increase the risk of sudden cardiac arrest. It can also occur in those without any apparent cause or warning signs. It is important to manage the risk factors through lifestyle modifications and regular medical checkups.

3. Signs and Symptoms of Sudden Cardiac Arrest

   Sudden cardiac arrest is characterized by a sudden loss of heart function occurring without any warning. The signs and symptoms are abrupt and can be severe.

   The signs and symptoms of sudden cardia arrest include: 

   • Sudden loss of consciousness
   • Absence of breathing or abnormal breathing
   • Loss of pulse or weak pulse

   Sudden cardiac arrest is known to be different from a heart attack. A heart attack occurs when the flow of blood to the heart is blocked, which is mostly due to a clot in the coronary arteries. Some symptoms of heart attack and sudden cardiac arrest may overlap but it is important to differentiate between the two conditions.

   If anyone experiences signs similar to those of sudden cardiac arrest, it is vital to take immediate action. Early recognition and immediate intervention can significantly improve the chances of survival for someone experiencing sudden cardiac arrest.

4. Chain of Survival in Sudden Cardiac Arrest

   The chain of survival is the concept that outlines the series of crucial steps to maximize the chances of survival and positive outcomes for individuals experiencing sudden cardiac arrest. 

   • The first step is recognizing the signs and activating the emergency response system. On witnessing someone experiencing sudden collapse, loss of consciousness, absence of breathing, or no pulse, it is essential to call the emergency medical service or the local emergency number.
   • Next, it is important to initiate cardiopulmonary respiration as quickly as possible. This involves performing chest compression and rescue breaths to maintain blood flow and oxygenation to the vital organs.
   • Next is to emphasize defibrillation. It is the most effective treatment for life-threatening arrhythmia. It is done using an automated external defibrillator. It is a portable device that analyzes the heart rhythm. It helps in improving survival rates.
   • Next comes the importance of advanced cardiac life support which involves the administration of advanced medical intervention and treatments by healthcare professionals. It is provided by healthcare professionals and paramedics once they arrive at the scene.

   The chain of survival is a continuous cycle. Each step relies on the prompt initiation of the previous step and seamless coordination between them.

5. Prevention of Sudden Cardiac Arrest

   Prevention plays a crucial role in reducing the risk of occurrence of sudden cardiac arrest. However, it is not always that with a healthy lifestyle, the risk of sudden cardiac death can be prevented but the risk can surely be reduced.

   Some of the key strategies include: 

   • Eating a healthy diet including a variety of fruits, vegetables, whole grains, lean proteins, and healthy fats. Also, one should limit the consumption of saturated fats, cholesterol, sodium, and added sugars.
   • Performing regular physical activity is also important. Engaging in 75 minutes of physical activity including training exercises at least twice a week can be helpful.
   • Avoiding alcohol and other substance abuse can prevent clot formation that contributes to sudden cardiac arrest. Also, alcohol consumption should be limited to one drink per day for women and two drinks per day for men.
   • The underlying health conditions should be managed which includes managing blood pressure levels, cholesterol levels, diabetes, and underlying heart conditions.
   • Knowing the family history one can assess the risk and recommend appropriate screenings.
   • One should stay up-to-date with medical check-ups and screening. Also, being aware of the signs and symptoms of heart disease and seeking medical attention promptly can be helpful in preventing the risk.
   • Learning CPR techniques and familiarizing yourself with the use of automated external defibrillator devices can significantly improve survival rates.

6.  Treatment and Outlook of Sudden Cardiac Arrest

   The main purpose of the treatment is to restart the heart which includes CPR and the use of a defibrillator.⁽³⁾

   Once the emergency service arrives, shock may be given to the heart, oxygen may be given and additional life support may be provided.

   Treatment may be needed for an underlying cause of the cardiac arrest. For example, if a person has sepsis he may need to stay in the hospital and use intravenous IV antibiotics.

7. Outlook

   In some cases, the heart may spontaneously begin beating again, which the doctor may relate to as a return of spontaneous circulation. In such a case the outlook is better.⁽³⁾ It is seen more in people without comorbidities.

   The outlook for sudden cardiac arrest is poor. It is reported by the Sudden Cardiac Arrest Foundation that only 10% of victims survive post sudden cardiac arrest.⁽⁴⁾ Lack of prompt care is a major factor in determining the survival rates. Seeking help and initiating CPR immediately is therefore important.

8. Conclusion

   Sudden cardiac arrest is a life-threatening condition that requires immediate intervention. Recognizing signs and symptoms of sudden cardiac arrest is important for initiating the Chain of Survival.

   Seeking emergency medical care and giving CPR or using a defibrillator.

   Every minute counts therefore there should be no delays.

   People who are at risk of sudden cardiac arrest should make sure to see a doctor and adopt a heart-healthy lifestyle and manage any underlying risks.

Also Read:

• Sudden Cardiac Arrest in Young Athletes : Identifying Risks and Prevention
• Uncommon Triggers of Sudden Cardiac Arrest : Exploring Lesser-Known Causes