Sudden Cardiac Arrest (SCA)

What is Sudden Cardiac Arrest?

Sudden Cardiac Arrest (SCA) is a life-threatening condition where the heart suddenly stops beating effectively due to a severe arrhythmia, often ventricular fibrillation. This results in the abrupt loss of blood flow to the brain and vital organs, leading to death within minutes if not treated immediately.

SCA is different from a heart attack, which is caused by a blockage in blood flow. However, a heart attack can trigger SCA. Immediate emergency response using CPR and an Automated External Defibrillator (AED) can double or triple survival chances.

Causes and Risk Factors

SCA is typically caused by electrical disturbances in the heart. Common causes and risk factors include:

• Coronary Artery Disease: The most common underlying cause of SCA.
• Previous Heart Attack: Scar tissue can disrupt electrical pathways in the heart.
• Cardiomyopathy: Structural heart problems can lead to arrhythmias.
• Arrhythmias: Especially ventricular fibrillation and ventricular tachycardia.
• Long QT Syndrome and Other Genetic Disorders: Inherited electrical disorders can lead to SCA.
• Drug Overdose or Severe Electrolyte Imbalance: Can disrupt the heart’s rhythm.
• Family History: Especially if relatives experienced sudden cardiac death.
• Recreational Drug Use: Cocaine and other stimulants can trigger arrhythmias.

Warning Signs and Symptoms

SCA often occurs without warning, but sometimes there are subtle symptoms beforehand. These may include:

• Chest Pain or Discomfort: Especially if related to underlying heart conditions.
• Shortness of Breath: May indicate an impending cardiac event.
• Unexplained Fatigue or Weakness: Especially in the days leading up to arrest.
• Sudden Collapse: The hallmark of SCA; the person becomes unresponsive with no breathing or pulse.
• Fainting or Lightheadedness: Often occurs seconds before cardiac arrest.
• No Symptoms: In many cases, the first sign is the arrest itself.

Emergency Response

Immediate action is critical during a sudden cardiac arrest. Steps include:

• Call Emergency Services: Dial emergency numbers immediately.
• Begin CPR: Start chest compressions hard and fast in the center of the chest.
• Use an AED: If available, follow the voice prompts to deliver a shock if needed.
• Continue CPR: Until emergency personnel arrive or the person shows signs of life.
• Don't Delay: Every minute without defibrillation reduces survival by 7–10%.

Prevention and Risk Management

Preventing SCA involves managing heart health and recognizing risks. Key strategies include:

• Manage Underlying Conditions: Treat coronary artery disease, high blood pressure, and diabetes.
• Screen for Genetic Risks: Get tested if there's a family history of sudden death or inherited arrhythmias.
• Implantable Cardioverter Defibrillator (ICD): Used in high-risk individuals to prevent sudden death.
• Medications: Beta-blockers, antiarrhythmics, or others as prescribed to control heart rhythm.
• Heart-Healthy Lifestyle: Quit smoking, maintain a healthy weight, and follow a cardiac-friendly diet.
• Avoid Triggers: Such as recreational drugs, excessive alcohol, and extreme exertion (in some individuals).

Living After a Cardiac Arrest

Survivors of SCA often need ongoing care to prevent recurrence. Key components of post-SCA life include:

• Cardiac Rehabilitation: Structured recovery program to improve physical and emotional health.
• ICD Monitoring: Regular checks if a defibrillator was implanted.
• Medication Compliance: Strict adherence to prescribed drugs is essential.
• Mental Health Support: Anxiety and PTSD are common; counseling may help.
• Emergency Planning: Educate family members on CPR and AED use, and keep emergency numbers accessible.