Cardiac Arrest: Immediate Recognition, CPR, and Survival Guide

Understanding Cardiac Arrest

Cardiac arrest is the sudden, unexpected loss of heart function, breathing, and consciousness. It's a MEDICAL EMERGENCY requiring immediate action. Unlike heart attack (myocardial infarction), which is a circulation problem, cardiac arrest is an electrical problem—the heart's electrical system malfunctions, causing the heart to stop beating effectively.

Each year, approximately 350,000-500,000 Americans experience cardiac arrest outside of hospitals. Survival rates are grim: only ~10% survive to hospital discharge. However, with immediate bystander CPR and AED use, survival can increase to 40-50% or higher.

Cardiac Arrest vs Heart Attack

| Feature | Cardiac Arrest | Heart Attack (Myocardial Infarction) | |---------|----------------|--------------------------------------| | Mechanism | Electrical malfunction → heart stops beating effectively | Blocked artery → heart muscle damaged | | Consciousness | Unresponsive, no breathing/agonal breathing | Usually conscious, breathing | | Pulse | No pulse (or ineffective pulse) | Pulse present | | Urgency | Immediate action required (seconds matter) | Rapid evaluation needed (minutes) | | Relationship | Heart attack can CAUSE cardiac arrest | Can lead to cardiac arrest if untreated |

Key point: A heart attack is a "plumbing" problem (blocked artery). Cardiac arrest is an "electrical" problem (heart stops beating). A heart attack can cause cardiac arrest, but most cardiac arrests are caused by other factors.

Recognizing Cardiac Arrest

Immediate Signs

• Unresponsiveness: Person doesn't respond to shouting or shaking
• No normal breathing: Absent or only gasping (agonal breathing)
• No pulse: No carotid pulse (if trained to check)

Agonal Breathing

Gasping, snorting, or moaning breathing is NOT normal breathing—it's a sign of cardiac arrest. Up to 40% of cardiac arrest patients have agonal breathing initially. Don't be fooled—START CPR if unresponsive and not breathing normally.

Performing CPR

Hands-Only CPR (For Untrained Bystanders)

The Goal: Maintain some blood flow to brain and vital organs until advanced care arrives.

Technique:

1. Position: Person on their back on firm surface
2. Hand placement: Heel of one hand in center of chest (nipple line), other hand on top, fingers interlaced
3. Body position: Shoulders directly over hands, elbows locked
4. Push: Push HARD (at least 2 inches/5 cm deep) and FAST (100-120 compressions/minute)
5. Allow recoil: Let chest come back up fully after each compression
6. Don't stop: Continue until:
   • EMS arrives and takes over
   • Person starts breathing normally
   • AED is ready to use
   • You're too exhausted to continue

Rhythm: Push to the beat of "Stayin' Alive" by Bee Gees (103 BPM), "Crazy in Love" by Beyoncé (115 BPM), or simply "1, 2, 3, 4..." at a steady, fast pace.

Conventional CPR (Trained Responders)

Ratio: 30 compressions : 2 breaths

Compressions:

• Same as hands-only (hard, fast, center of chest)
• Minimize interruptions (＜10 seconds)
• Don't over-ventilate (excessive breathing reduces compression effectiveness)

Breaths:

• Head tilt-chin lift to open airway
• Pinch nose, seal mouth, give 2 breaths
• Each breath: 1 second, visible chest rise
• If uncomfortable with breaths, continue hands-only CPR

Special Considerations

Pregnant Women: Same technique, but displace uterus to left if possible (have someone push uterus to left while performing CPR)

Obese Patients: Harder compressions needed, may need two hands stacked or two rescuers

Children (1 year to puberty):

• Use one hand for compressions
• Compress to 1/3 depth of chest (about 2 inches)

Infants (＜1 year):

• Two fingers in center of chest (just below nipple line)
• Compress to 1/3 depth of chest (about 1.5 inches)
• Ratio: 30:2 (single rescuer) or 15:2 (two rescuers)

Using an AED (Automated External Defibrillator)

AEDs are portable devices that analyze heart rhythm and deliver electric shock if needed. They're designed for public use—no medical training required.

Step-by-Step:

1. Turn on AED: Follow voice prompts
2. Attach pads:
   • Place one pad on upper right chest (below collarbone)
   • Place other pad on lower left chest (below armpit)
   • Remove excessive hair if necessary (pads won't stick)
   • Dry chest if sweaty/wet
3. Plug in pads (if not already connected)
4. Stand clear: AED will say "analyzing rhythm"—don't touch patient
5. Shock advised?:
   • If shock advised: "Stand clear," shout "CLEAR," ensure no one touching, press shock button
   • If no shock advised: Resume CPR immediately
6. After shock: Immediately resume CPR (don't check pulse)
7. Continue: Follow prompts until EMS arrives or patient wakes up

Causes and Risk Factors

Common Causes

1. Coronary Artery Disease (70% of cases):

   • Plaque rupture → clot formation → arrhythmia
   • Often undiagnosed CAD

2. Arrhythmias:

   • Ventricular fibrillation (most common shockable rhythm)
   • Ventricular tachycardia
   • Structural heart disease (cardiomyopathy, heart failure)

3. Structural Heart Disease:

   • Hypertrophic cardiomyopathy (common cause in young athletes)
   • Dilated cardiomyopathy
   • Valvular disease

4. Electrolyte Abnormalities:

   • Potassium (low or high)
   • Magnesium deficiency
   • Drug-induced (QT-prolonging medications)

5. Other Causes:

   • Drug overdose (opioids, cocaine)
   • Trauma (commotio cordis: chest blow)
   • Respiratory arrest (drowning, choking)
   • Massive pulmonary embolism

Risk Factors

• Previous heart attack (75% of cardiac arrest deaths occur in people with prior MI)
• Heart failure
• Arrhythmia history
• Family history of sudden cardiac death
• Drug use (cocaine, methamphetamines)
• Severe electrolyte imbalance
• Extreme physical stress (marathon running, intense exertion)

Prevention Strategies

For Known Heart Disease

• Medication adherence: Beta-blockers, ACE inhibitors reduce sudden death risk
• ICD (Implantable Cardioverter-Defibrillator): For high-risk patients
  • Detects dangerous arrhythmias
  • Delivers shock internally to restore normal rhythm
  • Reduces mortality by 50% in selected patients

For Everyone

• Know your risk: Regular checkups, screening for heart disease

• Lifestyle:

  • Don't smoke (quitting reduces risk by 50% in 5 years)
  • Exercise regularly (150 min/week moderate intensity)
  • Maintain healthy weight
  • Limit alcohol (max 1 drink/day women, 2 men)
  • Manage stress
  • Get adequate sleep

• Screening for athletes:

  • Pre-participation physical exam
  • Consider ECG screening for competitive athletes
  • Know family history of sudden death

• Learn CPR:

  • American Heart Association: 90-minute certification course
  • Red Cross: Various CPR/AED classes
  • Online resources: Hands-Only CPR videos

Survival Statistics

| Intervention | Survival Rate | |--------------|---------------| | No bystander action | 6-8% | | Bystander CPR only | 10-15% | | Bystander CPR + AED | 30-45% | | Early CPR + Early AED + Early ACLS | 40-50%+ |

Chain of Survival (AHA):

1. Recognition and activation: Recognize cardiac arrest, call 911
2. Immediate CPR: Start chest compressions
3. Rapid defibrillation: Use AED as soon as available
4. Advanced life support: EMS provides medications, airway management
5. Post-cardiac arrest care: Hospital treatment, targeted temperature management

Related Conditions

• Heart Attack: Can lead to cardiac arrest
• Heart Failure: Increases cardiac arrest risk
• Arrhythmias: Can cause cardiac arrest

FAQ

References