What is sudden cardiac arrest (SCA)?

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From the Guidelines

Sudden cardiac arrest is a life-threatening emergency where the heart suddenly stops beating, causing blood flow to the brain and vital organs to cease, and it requires immediate recognition and treatment with CPR and defibrillation to improve survival rates. It occurs when the heart's electrical system malfunctions, often due to ventricular fibrillation (chaotic heart rhythm) 1. Unlike a heart attack where blood flow is blocked but the heart continues beating, cardiac arrest means the heart stops functioning completely. Common causes include coronary heart disease, heart attack, electrolyte imbalances, severe physical stress, and certain genetic disorders. Symptoms include sudden collapse, loss of consciousness, no pulse, and no breathing.

Key Points to Consider

  • Immediate treatment is crucial and involves calling emergency services, performing CPR, and using an automated external defibrillator (AED) if available 1.
  • The chain of survival includes early recognition, early CPR, early defibrillation, and advanced medical care.
  • Without prompt intervention, brain damage begins within minutes, and death can occur within 8-10 minutes.
  • Survival rates improve significantly with immediate bystander CPR and defibrillation, highlighting why learning basic life support skills is important for everyone 1.

Management and Treatment

  • Management of SCA involves prompt recognition, immediate cardiopulmonary resuscitation (CPR) and early defibrillation 1.
  • Any person who collapses without contact with another person or obstacle should be regarded as being in SCA until proven otherwise.
  • An automated external defibrillator (AED), or manual defibrillator if an AED is not available, should be immediately accessible during emergencies.

From the Research

Definition of Sudden Cardiac Arrest

  • Sudden cardiac arrest is a major public health problem in the United States, accounting for approximately 350,000 deaths annually 2.
  • It is caused by a ventricular arrhythmia, which can be treated with early defibrillation 3.
  • Sudden cardiac arrest often occurs at home, where an automated external defibrillator (AED) is usually unavailable until emergency medical services (EMS) arrive 2.

Characteristics of Sudden Cardiac Arrest

  • The time from a 911 call to shock averages approximately 7 minutes in urban areas and is more than 14.5 minutes in rural environments 2.
  • Survival from cardiac arrest decreases by approximately 7 to 10% per minute of ventricular arrhythmia 2.
  • The most common location of out-of-hospital sudden cardiac arrest is the home, where emergency medical services are challenged to provide timely care 4.

Treatment and Prevention

  • Early defibrillation has been shown to be critical to improving survival from sudden cardiac arrest 3.
  • The use of AEDs by first responders and laypersons has reduced time to defibrillation and improved survival from sudden cardiac arrest in several communities 3.
  • A prearrest protocol is proposed for the at-home use of fully automated external defibrillators in select cardiac patients, which should reduce the arrest-to-shock interval to under 1 minute and may eliminate the need for CPR in some cases 2.

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Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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