PEA: When the Heart's Electrical Signals Fail Without Warning

Pulseless electrical activity (PEA) is an especially serious heart arrhythmia related to weak or undetectable electrical activity. PEA can be a precursor to sudden cardiac death, so its symptoms require immediate medical attention.

The beating of your heart is powered by an electrical system that maintains a steady rhythm of contractions and rests 24 hours a day.

Abnormal rhythms are called arrhythmias. They can be mild and relatively harmless or severe and life threatening. They often stem from other heart problems, such as a heart attack, or other physical trauma.

Pulseless electrical activity (PEA) is a type of abnormal heart rhythm. It occurs when the electrical activity in your heart is too weak to maintain a heartbeat or to pump blood through your body.

PEAs can progress to sudden cardiac arrest if not treated. PEA is considered a medical emergency that requires immediate .

PEAs often stem from other heart problems, such as a heart attack, or other physical trauma. While PEAs can't always be prevented, maintaining good cardiovascular health and working with a doctor if you have any type of arrhythmia or other heart condition may help lower your risk.

What is pulseless electrical activity (PEA)?

PEA is an arrhythmia in which the heart's electrical activity has become so weak, it can't make the heart contract effectively and a pulse is impossible to detect. PEA may take two similar but distinct forms: pseudo-PEA and true PEA.

Pseudo-PEA

Pseudo-PEA describes electrical activity that can still cause the heart to contract slightly and pump some blood. However, heart function is still too weak to pump enough blood to meet the body's demands. Because a pulse can't be found, only an electrocardiogram (EKG) can identify the reduced electrical flow in the heart.

A suggests that the incidence of pseudo-PEA is increasing and that it may be more common than previously estimated. This may be due, in part, to significantly less research on pseudo-PEA than true PEA.

True PEA

True PEA means there is faint electrical activity in the heart, but not enough to make it contract or produce a detectable pulse. It also means no blood is being pumped into or out of the heart.

PEA and asystole: What's the difference?

While PEA means there is some electrical flow in the heart muscle, asystole is a condition in which all electrical activity in the heart has completely stopped.

Asystole is commonly known as "flatlining." It can be fatal if the heart's pumping ability isn't restarted within minutes. Both PEA and asystole can lead to cardiac arrest.

What are the primary causes of PEA?

PEA occurs when the heart suffers major trauma, such as a heart attack. A suggests that a significant percentage of PEA cases result from a loss of blood flow in the heart muscle, usually brought on by a blockage in a coronary artery.

PEA can also occur if a condition affecting metabolism, circulation, or respiration also causes an abnormal heart rhythm to develop.

Some possible causes of PEA are:

• high levels of acid in the bloodstream (acidosis)
• high (hyperkalemia) or low (hypokalemia) potassium levels
• dehydration (hypovolemia)
• body temperature drops below 95°F/35°C (hypothermia)
• dangerously low levels of oxygen in the organs ()
• thrombosis (coronary or pulmonary)
• chest trauma (commotio cordis)
• heart toxins
• cardiac tamponade

The risk of PEA increases , especially among females.

What are the symptoms of PEA?

The primary symptoms of PEA include:

• electrical activity only detectable on an EKG
• no discernible pulse
• no heartbeat detectable with a stethoscope
• pauses in breathing (or the stoppage of breathing altogether)

How is PEA diagnosed?

An electrocardiogram (EKG) is the only way to detect electrical activity in a heart affected by PEA. Other tests doctors use to diagnose PEA can include:

• arterial blood gas analysis, which measures oxygen and carbon dioxides levels in your arteries
• core body temperature
• echocardiogram
• serum electrolytes panel, checking for levels of sodium, potassium, and other minerals that support healthy heart function

How is PEA treated?

Treating PEA usually requires CPR, especially if the person is outside a hospital setting.

If PEA is suspected, someone who knows CPR should perform the lifesaving technique until an ambulance arrives.

Administering epinephrine, the chemical term for adrenaline, may also help restart the heart.

When the underlying cause of PEA can be determined, it should also be treated. For example, if dehydration is to blame, then giving a person fluids and restoring healthy electrolyte levels is appropriate.

Can defibrillation (electric shock) restore the heart of someone with PEA to a normal rhythm?

PEA is considered a "non-shockable" arrhythmia, meaning defibrillation is not an appropriate treatment. If CPR restarts cardiac activity but a shockable arrhythmia is present, such as ventricular tachycardia, then defibrillation may be safe and effective.

Takeaway

PEA is a life threatening arrhythmia. It can develop due to several cardiovascular and respiratory problems and metabolic disorders affecting the heart's energy reserves.

If you encounter someone who seems to be experiencing PEA, call 911 or local emergency services and begin CPR immediately.

Preventing PEA from progressing to cardiac arrest may be the only way to save a person's life. If you or a loved one recover from PEA, discuss ways to lower your risk of the condition returning with a cardiologist.