Pulseless Electrical Activity (PEA) on ECG

Introduction

Pulseless Electrical Activity (PEA) is a critical condition in which the heart's electrical activity continues, but there is no effective cardiac output. This means that despite electrical signals being present on an ECG, the heart is not pumping blood to the body.

PEA is one of the non-shockable cardiac arrest rhythms, meaning it does not respond to defibrillation. Instead, treatment focuses on identifying and addressing the underlying cause.

Causes (The 6 H’s and 5 T’s)

PEA is often caused by reversible conditions that should be rapidly identified and corrected:

H’s: 1. Hypoxia – Low oxygen levels leading to ineffective heart function. 2. Hypovolemia – Severe blood or fluid loss. 3. Hydrogen ion (acidosis) – Metabolic or respiratory acidosis. 4. Hyperkalemia / Hypokalemia – Dangerous potassium imbalances. 5. Hypothermia – Extremely low body temperature affecting cardiac function. 6. Hypoglycemia (sometimes included) – Critically low blood sugar levels.

T’s: 1. Tension pneumothorax – Air trapped in the chest cavity compressing the heart. 2. Tamponade (cardiac) – Fluid buildup in the pericardium preventing heart contraction. 3. Toxins – Drug overdose or poisoning affecting cardiac function. 4. Thrombosis (pulmonary) – Pulmonary embolism blocking blood flow to the lungs. 5. Thrombosis (coronary) – Myocardial infarction (heart attack) causing cardiac arrest.

ECG Findings

ECG in PEA may show any organized electrical activity except for ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT). Common patterns include: - Bradycardia (slow rhythm) - Narrow complex tachycardia - Normal sinus rhythm - Wide complex rhythms

However, the key feature is the absence of a palpable pulse despite these electrical signals.

Management and Treatment

1. CPR (Cardiopulmonary Resuscitation) – Immediate high-quality CPR is critical to maintaining circulation.
2. Epinephrine – Administer 1 mg IV every 3–5 minutes to improve circulation.
3. Identify and Treat the Underlying Cause – Rapid recognition of reversible causes is essential to improving survival.
4. Airway and Oxygenation – Ensure adequate ventilation and oxygen delivery.
5. Continuous Monitoring and Ultrasound – Point-of-care ultrasound (POCUS) can help diagnose conditions like tamponade or pulmonary embolism.

Prognosis

The outcome depends on how quickly the underlying cause is identified and treated. If left untreated, PEA progresses to asystole (complete absence of electrical activity), which is associated with very poor survival rates.

Conclusion

PEA is a medical emergency requiring immediate CPR and identification of reversible causes. Understanding the 6 H’s and 5 T’s can help in rapid diagnosis and treatment. If you suspect someone is in cardiac arrest with no pulse but an ongoing ECG rhythm, seek emergency medical attention immediately.

Source recommendations

1. American Heart Association (AHA) Advanced Cardiovascular Life Support (ACLS) Guidelines

1. https://cpr.heart.org/en/resuscitation-science/cpr-and-ecc-guidelines/algorithms
2. https://www.ahajournals.org/doi/10.1161/CIR.0000000000001194
3. https://cpr.heart.org/en/resuscitation-science/cpr-and-ecc-guidelines/adult-basic-and-advanced-life-support
4. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000916
5. https://shopcpr.heart.org/acls-provider-manual

2. European Resuscitation Council (ERC) Guidelines for Resuscitation

1. https://cprguidelines.eu/guidelines-2021
2. https://www.erc.edu/
3. https://cprguidelines.eu/
4. https://pubmed.ncbi.nlm.nih.gov/26477410/
5. https://www.resuscitationjournal.com/article/S0300-9572(21)00063-0/fulltext