Pulseless Electrical Activity

What is pulseless electrical activity?

Pulseless electrical activity (PEA) is a condition where your heart stops. The electrical activity in your heart doesn't generate a heartbeat. When your heart stops, you go into cardiac arrest, and you don’t have a pulse.

PEA is a “nonshockable” heart rhythm, meaning a defibrillator won’t correct it. If not treated quickly, PEA causes sudden cardiac death within minutes.

How does pulseless electrical activity work?

At the beginning of every normal heartbeat, a cluster of cells (the sinoatrial node) near the top of your heart creates an electrical current, which then spreads to other areas of your heart. As the current passes through the heart muscle, the muscle reacts by flexing. That causes your heart to squeeze and pump blood.

That electrical current is detectable with a diagnostic test called an electrocardiogram (ECG or EKG). With PEA, your heart does have a detectable electrical current, but your heart isn’t strong enough to pump blood to the body.

PEA can take two different forms:

• Pseudo-PEA: This is a type of PEA where the electrical activity in your heart does cause your heart muscle to squeeze very weakly. That squeezing does move some blood, but it isn’t a proper heartbeat and it isn’t strong enough to pump blood effectively, so you still don’t have a pulse.
• True PEA: This is PEA where your heart has electrical activity, but your heart muscle isn’t reacting to it. That means blood isn’t moving at all and you don’t have a pulse.

Time is critical. When someone's heart stops, call 911 and start CPR by performing chest compressions immediately to improve their chance of surviving.

Pulseless electrical activity vs. asystole: What’s the difference?

PEA and asystole (also known as “flat-lining”) can lead to cardiac arrest. The difference is that with PEA, your heart still has some detectable electrical activity. With asystole, there’s no electrical activity to detect.

What are the most common causes of pulseless electrical activity?

The causes of PEA fall into two distinct categories.

Primary PEA

This happens because of a problem with your heart itself.

Secondary PEA

This is PEA from a distinct outside cause rather than from a problem with your heart itself. The most likely causes of secondary PEA are:

• Blood loss or low blood pressure.
• Low oxygen levels.
• Severe dehydration or other electrolyte problems.
• Heart attack (myocardial infarction).
• Pulmonary embolism.
• Hypothermia (low body temperature).
• Trauma (either directly to the heart or to the chest overall).
• Air, blood or fluid filling areas inside your chest, putting so much pressure on your heart that it can’t beat correctly.
• Toxic effects. Drugs (prescription or recreational) and other toxic substances can affect your heart, causing PEA.

How common is PEA?

PEA occurs in about 20% of sudden heart-related deaths outside of hospitals. Inside hospitals, it accounts for about 10% of heart-related deaths.

How is this problem treated?

The only way to know if a stopped heart involves PEA is with an electrocardiogram, which isn’t always available outside of a hospital setting. Fortunately, the treatment for cardiac arrest is always the same, regardless of whether or not PEA is involved.

Immediate, effective CPR, delivering chest compressions, should always be the top priority when cardiac arrest happens, especially outside of a hospital setting. CPR should continue until emergency services or first responders arrive.

If PEA happens inside a hospital, the following treatments are likely:

• CPR. This is always a key part of treatment inside and outside the hospital environment.
• Epinephrine. This medication, also known as adrenaline, can help restore your heart to a normal rhythm.
• Treating the cause of PEA. Secondary PEA means it has a specific cause such as blood loss, electrolyte problems, etc. Treating the specific cause can help return your heart to a normal rhythm.

Is PEA a shockable rhythm?

Certain malfunctions in your heart’s electrical system that create arrhythmias are “shockable.” That means defibrillation (an electric shock) can stop those rhythms by restoring your heart to a normal rhythm.

The cardiac arrests with shockable rhythms are ventricular fibrillation and pulseless ventricular tachycardia. Both of those can turn into PEA, but PEA itself isn’t shockable. However, CPR for pulseless electrical activity can sometimes get your heart to switch to a shockable rhythm. If that happens, then defibrillation can happen, which has a chance of restoring your heart to a normal rhythm.

Can you avoid developing PEA?

PEA doesn’t happen predictably, and it’s a common part of the normal dying process. While it might be possible to revive someone who has PEA, this isn’t always possible, even if you begin CPR right away.

When should this symptom be treated by a doctor or healthcare provider?

Cardiac arrest is always a medical emergency that needs immediate care. You should always call 911 (or the local emergency services number in your area) and start CPR. If you don’t know CPR, 911 operators can often instruct you over the phone on how to give CPR.

The main symptoms of cardiac arrest are:

• Fainting or passing out unexpectedly.
• If you can’t feel a pulse on the person’s neck or wrist.
• Fighting to breathe or not breathing at all.

A note from Cleveland Clinic

Pulseless electrical activity is a type of cardiac arrest. Fortunately, modern medicine’s understanding of PEA and similar conditions has grown tremendously over the past few decades. However, the first few moments are especially critical. That means effective CPR and quick medical attention can make a big difference and improve the chances of survival.