Lesson 5 – Cardiac Arrest Recognition and Initial Actions

Hello and welcome to the fifth lesson of this course on Cardiac Emergencies.

This lesson focuses on identifying cardiac arrest and the immediate actions to take. It covers recognizing cardiac arrest, distinguishing respiratory vs cardiac arrest, AED use, shockable rhythms, asystole, PEA, and initial CPR steps. Good studying.

Recognizing cardiac arrest.

Key signs: sudden loss of consciousness, no normal breathing, no pulse or circulation signs. Beware agonal respirations (irregular gasps) that mimic breathing but are ineffective. Check breathing and pulse for no more than 10 seconds before starting CPR. Quick recognition improves survival chances.

Difference between respiratory arrest and cardiac arrest.

Respiratory arrest: no breathing but pulse present—start rescue breathing. Cardiac arrest: no breathing and no pulse—start full CPR immediately. This distinction guides correct intervention.

Role of AED in cardiac arrest.

AED identifies shockable rhythms: ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT). When AED says “Shock Advised,” deliver shock immediately after clearing the patient. Early defibrillation improves outcomes.

Ventricular fibrillation (V-fib) and ventricular tachycardia (V-tach).

V-fib: chaotic ventricular quivering, no effective pumping, no pulse, irregular waves on monitor. V-tach: fast ventricular rhythm; pulseless V-tach means no pulse despite electrical activity. AED shocks these rhythms; if no shock advised, continue CPR per protocol.

Asystole ("flatline").

No electrical activity in heart; AED shows “No Shock Advised.” Not treatable by defibrillation. Focus on high-quality CPR, rescue breaths, and request ALS backup per AHA protocol.

Pulseless Electrical Activity (PEA).

Electrical activity present but no effective heart pumping or pulse. ECG may show stable rhythm, but patient is in arrest. AED advises no shock. Treat with high-quality CPR and search for reversible causes (“H’s and T’s”).

The “H’s and T’s” – reversible causes of cardiac arrest.

H’s: Hypovolemia (blood loss), Hypoxia (low oxygen), Hydrogen ion (acidosis), Hypo/Hyperkalemia, Hypothermia. T’s: Toxins, Tamponade (cardiac), Tension pneumothorax, Thrombosis (cardiac/pulmonary). Recognizing these guides treatment and communication with ALS.

Immediate actions upon recognizing cardiac arrest.

Ensure scene safety first. Confirm unresponsiveness and no breathing. Call for ALS and help. Start high-quality CPR immediately with chest compressions first. Apply AED ASAP and follow prompts. Assign roles if multiple rescuers present for efficiency.

CPR protocol awareness.

Follow current CPR guidelines. Research and protocols evolve annually to improve outcomes in pre-hospital cardiac arrests. Stay updated with latest standards.

Example of AED use by EMT.

Visual of EMT using AED on collapsed patient as first responder. Demonstrates proper AED application and early intervention importance.