Pulseless electrical activity (PEA) is a cardiac arrest rhythm in which a heart monitor shows organized electrical signals moving through the heart, yet the heart is not pumping blood well enough to produce a detectable pulse. It is one of the rhythms emergency teams look for the moment someone collapses, because how a rhythm is classified changes what treatment happens next. This guide explains what pulseless electrical activity means, how it differs from other arrest rhythms like asystole and ventricular fibrillation, what commonly causes it, how emergency teams recognize and treat it, and what family members should understand about the process. Throughout, the goal is context and clarity, not guidance for managing a cardiac arrest at home. Pulseless electrical activity is always a medical emergency that requires calling 911 and starting CPR right away.
What pulseless electrical activity means
In a normally functioning heart, an electrical signal starts in the sinoatrial node and spreads through the heart muscle, triggering a coordinated squeeze that pushes blood out to the body. Clinicians describe this expected pattern as a normal sinus rhythm, and a heart monitor or electrocardiogram (ECG, a test that records the heart’s electrical signals) shows this activity as a repeating wave pattern. In pulseless electrical activity, that wave pattern is still present, sometimes even looking close to normal, but the mechanical pumping action has failed or become too weak to generate a pulse a rescuer can feel. Clinicians sometimes call this electromechanical dissociation, because the electrical and mechanical parts of the heartbeat have become disconnected from one another.
PEA is not one single disease. It is a description of what the heart is doing at a specific moment, and it can result from many different underlying problems, some of which are readily treatable if identified quickly. That is why the emergency response to PEA centers as much on finding the cause as on performing chest compressions.
How PEA differs from other cardiac arrest rhythms
Cardiac arrest rhythms are typically grouped into shockable and non-shockable categories, and understanding this distinction helps explain why treatment differs so much between them.
PEA versus asystole
Asystole is the complete absence of electrical activity in the heart, often described as a flatline on the monitor. PEA, in contrast, still shows organized or semi-organized electrical activity, just without an effective pump action behind it. Both are classified as non-shockable rhythms, meaning a defibrillator shock will not help either one, and both call for the same core response of high-quality CPR, epinephrine, and a search for reversible causes. Research comparing the two rhythms during in-hospital cardiac arrest found that patients with an initial PEA rhythm were somewhat more likely to achieve return of spontaneous circulation (ROSC, the heart restarting on its own) than those with asystole, though survival to hospital discharge ended up being similar between the two groups.
PEA versus ventricular fibrillation and pulseless ventricular tachycardia
Ventricular fibrillation (V-fib) and pulseless ventricular tachycardia are chaotic or excessively rapid electrical rhythms that prevent the heart from pumping effectively. Unlike PEA, these rhythms are shockable, meaning a defibrillator can often interrupt the abnormal electrical pattern and allow a normal rhythm to return. This is one of the most important distinctions for family members to understand: seeing someone use an automated external defibrillator (AED) at an airport or gym is aimed at shockable rhythms, not at PEA. When the underlying rhythm is PEA, an AED will typically advise against a shock, because delivering one would not address the actual problem. Emergency teams often document a related bedside finding called regular rate and rhythm when a heartbeat sounds steady on exam, which is a separate concept from the rhythm classification captured on a cardiac monitor during arrest.
What causes pulseless electrical activity
Because PEA reflects many different possible problems, emergency clinicians use a memory framework often called the H’s and T’s to run through the most common reversible causes systematically during resuscitation. Working through this list quickly, alongside CPR, gives the best chance of correcting the underlying issue.
| Reversible cause | What it means |
|---|---|
| Hypovolemia | Severe blood or fluid loss leaves too little volume in the circulation for the heart to pump effectively. |
| Hypoxia | Very low oxygen levels in the blood, often from a breathing problem, prevent the heart muscle from functioning normally. |
| Hydrogen ion excess (acidosis) | A buildup of acid in the blood, common after prolonged low blood flow, can impair the heart’s electrical and mechanical function. |
| Hyperkalemia or hypokalemia | Abnormally high or low potassium (an electrolyte that helps carry the heart’s electrical signals) can disrupt the heartbeat. |
| Hypothermia | A dangerously low body temperature can slow or stop effective heart pumping. |
| Tension pneumothorax | Trapped air in the chest cavity presses on the heart and major blood vessels, blocking blood flow. |
| Tamponade (cardiac) | Fluid collects around the heart in the pericardial sac, squeezing the heart chambers and preventing them from filling with blood. |
| Toxins | Certain medication overdoses or poisonings can directly disrupt heart muscle or electrical function. |
| Thrombosis (pulmonary) | A large blood clot blocking the lung’s blood vessels prevents blood from reaching the left side of the heart. |
| Thrombosis (coronary) | A blood clot blocking a heart artery, as in a heart attack, can severely weaken the heart’s pumping ability. |
Not every reversible cause applies in every case, and emergency teams prioritize the possibilities that fit the person’s history and the circumstances of the collapse. For example, a young person who collapsed after a chest injury raises concern for tension pneumothorax or tamponade, while someone with kidney disease raises concern for a potassium imbalance. A blood gas measurement called base excess can also help the team recognize a severe acid buildup as a contributing factor.
How PEA is recognized and treated in emergency settings
Recognition of PEA starts with the same first steps used for any suspected cardiac arrest: checking responsiveness, checking for normal breathing, and checking for a pulse. When a rescuer or clinician finds no pulse despite organized activity showing on a monitor, PEA is the working diagnosis, and the emergency response begins immediately.
The core of PEA treatment mirrors the broader approach to non-shockable cardiac arrest rhythms. High-quality chest compressions are started right away, with a compression depth of about two inches and a rate of roughly 100 to 120 compressions per minute, allowing the chest to fully recoil between compressions to help blood return to the heart. Clinicians establish intravenous access or intraosseous (into the bone marrow) access so that epinephrine, a medication that helps direct blood flow to the heart and brain during CPR, can be given approximately every three to five minutes. Advanced airway management may be added to support oxygenation and ventilation without significantly interrupting compressions, and orders during this phase are typically marked STAT to signal that every step must happen without delay.
Alongside these steps, the emergency team works through the reversible-causes framework, often using point-of-care ultrasound (POCUS, a portable bedside ultrasound) to look for clues such as fluid around the heart, a collapsed lung, or evidence of a large blood clot, all while keeping interruptions to chest compressions as brief as possible. A large systematic review of this ultrasound approach found that while it can feasibly identify some reversible causes of arrest during active resuscitation, the certainty of the underlying evidence remains low, meaning ultrasound findings are used as one clue among several rather than a stand-alone answer. The newest American Heart Association guidance, published in 2025, continues to support point-of-care ultrasound as an adjunct during advanced life support when it does not meaningfully interrupt chest compressions, alongside refined criteria for when resuscitation efforts might reasonably be stopped.
If the underlying cause is identified, treatment shifts to correcting it directly, such as giving IV fluids for hypovolemia, decompressing the chest for a tension pneumothorax, or giving calcium and other medications for a severe potassium imbalance. Correcting the cause, alongside continued CPR, offers the best chance of restoring an effective heartbeat.
Why defibrillation does not work for PEA
One of the most important things to understand about PEA is that it is a non-shockable rhythm, and delivering an electric shock will not restore an effective heartbeat. Defibrillation works by briefly stopping all electrical activity in the heart at once, giving the heart’s natural pacemaker a chance to restart a coordinated rhythm from scratch. This approach helps in rhythms like ventricular fibrillation, where the problem is chaotic, disorganized electrical activity. In PEA, the heart’s electrical system is already producing an organized signal; the problem lies in the mechanical response or an underlying condition preventing effective pumping. Shocking an already organized rhythm does not fix a mechanical or metabolic problem, and automated external defibrillators are specifically programmed to recognize this and recommend against a shock for PEA. This is why bystanders performing CPR on someone with PEA will typically be guided by the AED to continue compressions rather than to deliver a shock, and why continuing chest compressions and calling for emergency help remain the correct actions.
Survival factors and outcomes
Survival from PEA-related cardiac arrest depends heavily on how quickly it is recognized, how quickly high-quality CPR begins, how quickly emergency medical services arrive, and whether a reversible cause can be found and treated. A community-based study of out-of-hospital cardiac arrest identified younger age, having the arrest witnessed by someone else, occurring in a public location or healthcare setting rather than at home, and having certain pre-existing respiratory conditions as factors linked to better survival among people whose initial rhythm was PEA. People living with Herzinsuffizienz or other structural heart disease face a higher baseline risk of cardiac arrest generally, which is part of why managing those underlying conditions matters for long-term prevention. Notably, the study found that survival among witnessed PEA arrests remained meaningfully better than expected even when the emergency response took longer than ten minutes to arrive, which reinforces why starting CPR immediately, rather than waiting for paramedics, matters so much.
Separately, research comparing outcomes for PEA against asystole during in-hospital cardiac arrest found that although patients presenting with PEA were somewhat more likely to regain a pulse during resuscitation, this advantage did not translate into a meaningfully higher rate of surviving to hospital discharge, underscoring that achieving ROSC is an important milestone but not the same as long-term survival. These findings, taken together, highlight why bystander CPR, rapid emergency response, and hospital-based care to identify and treat the underlying cause all play connected roles in outcomes.
What family members should know
Understanding pulseless electrical activity can help family members follow what is happening during and after a loved one’s cardiac arrest, ask informed questions of the care team, and feel more prepared in a general sense, not to attempt to manage a cardiac arrest without professional help. If someone collapses, is unresponsive, and is not breathing normally, the correct actions are always the same: call 911 immediately, begin CPR if you are able, and use an AED if one is available, letting the device guide whether a shock is advised. Cardiac arrest is never something to observe and wait out at home; every minute without CPR and emergency care meaningfully lowers the chance of survival.
After a cardiac arrest is stabilized in the hospital, family members often hear the care team discuss the initial rhythm, the suspected or confirmed cause, and the plan for further testing such as an echocardiogram (a heart ultrasound) or coronary angiography (imaging of the heart’s arteries). If brain function is a concern after a prolonged arrest, the team may also track a bedside tool called the Glasgow Coma Scale to monitor a person’s level of consciousness over time. Understanding that PEA describes a pattern rather than a single diagnosis can make these conversations easier to follow, since the news may shift as tests reveal the specific underlying condition. In some cases, especially with advanced age or serious pre-existing illness, these events also prompt families to revisit documents like a do-not-resuscitate order or a do-not-intubate order with their care team, conversations that are entirely separate from how an active, unexpected cardiac arrest in someone without such directives should be handled. Taking a CPR course through a recognized provider such as the American Heart Association or American Red Cross is one of the most useful steps a family member can take, since bystander CPR started before emergency medical services arrive is strongly associated with better outcomes across all non-shockable and shockable rhythms alike.
Neueste wissenschaftliche Erkenntnisse
Emergency medicine research on pulseless electrical activity has focused heavily on two areas in the last few years: bedside ultrasound during resuscitation and updated national resuscitation guidelines. A 2022 systematic review looked specifically at whether point-of-care ultrasound performed during CPR can reliably identify the cause of cardiac arrest. The review found that ultrasound can feasibly detect certain causes, such as fluid around the heart or evidence suggesting a blood clot in the lungs, but the overall quality of the supporting studies was low and inconsistent, meaning ultrasound works best as one supporting clue for clinicians rather than a definitive test on its own. In plain terms, this tells families and patients that bedside ultrasound is a helpful tool doctors may use during a resuscitation, but it is used carefully alongside other information rather than as a single deciding factor.
The most significant recent development is the American Heart Association’s 2025 update to its Adult Advanced Life Support guidelines, published in the journal Circulation in October 2025. This comprehensive update reaffirms that both PEA and asystole require the same core response of immediate high-quality CPR, epinephrine given at regular intervals, and a structured search for reversible causes, while also refining guidance on point-of-care ultrasound use during resuscitation and on when it may be reasonable for emergency responders to stop resuscitation efforts based on established criteria. For readers, the practical takeaway is reassuring: the fundamentals of responding to a non-shockable arrest rhythm, calling 911 and starting compressions right away, remain the same and continue to be reinforced by the newest national guidance rather than replaced by it.
Separate research comparing PEA and asystole during in-hospital cardiac arrest, drawing on a large nationwide resuscitation registry, found that these two non-shockable rhythms behave somewhat differently in terms of achieving return of spontaneous circulation, even though long-term survival outcomes were similar between them. This distinction supports why current guidelines and hospital protocols increasingly treat PEA as its own recognizable pattern with its own set of likely causes, rather than lumping it together with asystole as simply “not a shockable rhythm.”
Glossar
| Begriff | Definition |
|---|---|
| Pulseless electrical activity (PEA) | A cardiac arrest rhythm showing organized electrical activity on a monitor without a detectable pulse. |
| Asystole | The complete absence of electrical activity in the heart, sometimes called a flatline. |
| Ventricular fibrillation (V-fib) | A chaotic, disorganized electrical rhythm that prevents the heart from pumping blood; it is a shockable rhythm. |
| Return of spontaneous circulation (ROSC) | The point during resuscitation when the heart restarts pumping on its own and a pulse returns. |
| Point-of-care ultrasound (POCUS) | A portable bedside ultrasound used by clinicians to look for possible causes of cardiac arrest during resuscitation. |
| Automated external defibrillator (AED) | A portable device that analyzes heart rhythm and delivers an electric shock only when the rhythm is shockable. |
| Cardiopulmonary resuscitation (CPR) | Chest compressions, with or without rescue breaths, used to keep blood circulating during cardiac arrest. |
| Hypovolemia | A significantly reduced volume of blood or fluid in the circulatory system. |
| Tension pneumothorax | A buildup of trapped air in the chest cavity that presses on the heart and lungs and blocks blood flow. |
| Cardiac tamponade | A collection of fluid around the heart that compresses the heart chambers and limits blood filling. |
FAQ
Is pulseless electrical activity the same as a heart attack?
No. A heart attack happens when blood flow to part of the heart muscle is blocked, often by a clot in a coronary artery. Pulseless electrical activity is a type of cardiac arrest rhythm, meaning the heart has stopped pumping effectively. A heart attack can be one of several possible causes that lead to PEA, but the two terms describe different things.
Can someone survive pulseless electrical activity?
Yes, survival is possible, and outcomes improve significantly with immediate bystander CPR, a fast emergency medical response, and prompt identification of a treatable underlying cause. Survival rates for PEA arrests have historically been lower than for shockable rhythms like ventricular fibrillation, but research shows meaningful numbers of people do survive, particularly when the arrest is witnessed and CPR starts right away.
Why doesn’t a defibrillator shock help with PEA?
A defibrillator shock is designed to interrupt chaotic electrical activity, such as ventricular fibrillation, so the heart’s natural pacemaker can restart a coordinated rhythm. In PEA, the heart’s electrical signal is already organized; the problem is that this signal isn’t producing an effective pump action, often because of an underlying issue like severe fluid loss or a blocked blood vessel. A shock does not address that underlying problem, which is why AEDs recommend against shocking a PEA rhythm.
What should I do if I think someone near me is in cardiac arrest?
Call 911 or your local emergency number immediately, then begin CPR if you’re able, focusing on hard, fast chest compressions. If an AED is available, turn it on and follow its voice prompts; the device will advise whether a shock is appropriate. Continue CPR until emergency medical personnel arrive and take over, or until the person begins to breathe or move on their own.
Does PEA always mean someone will need long-term care afterward?
Not necessarily. Outcomes after PEA-related cardiac arrest vary widely depending on how quickly the person received CPR, how quickly the underlying cause was found and treated, and their overall health beforehand. Some people recover well, while others may need extended hospital care, rehabilitation, or ongoing monitoring for the condition that caused the arrest. The care team can give more specific information based on individual circumstances.
Is PEA more common in certain settings, like hospitals versus outside the hospital?
PEA and asystole together account for the majority of initial rhythms seen during in-hospital cardiac arrest, and PEA occurs outside hospitals as well. Because PEA can stem from so many different causes, from severe allergic reactions to blood clots to electrolyte imbalances, it appears across many different clinical situations rather than being tied to one specific setting.
Quellen
- Wigginton JG, et al. — Part 9: Adult Advanced Life Support: 2025 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care — Circulation, 2025 — pubmed.ncbi.nlm.nih.gov
- Reynolds JC, et al. — Diagnostic Test Accuracy of Point-of-Care Ultrasound During Cardiopulmonary Resuscitation to Indicate the Etiology of Cardiac Arrest: A Systematic Review — Resuscitation, 2022 — consensus.app
- Andrea L, et al. — Pulseless electrical activity and asystole during in-hospital cardiac arrest: Disentangling the ‘nonshockable’ rhythms — Resuscitation, 2023 — pubmed.ncbi.nlm.nih.gov
- Oregon Sudden Unexpected Death Study / Ventura PRESTO investigators — Determinants of survival in sudden cardiac arrest manifesting with pulseless electrical activity — Resuscitation, 2023 — consensus.app
- American Heart Association — Treatment of Cardiac Arrest — heart.org, 2025 — heart.org
- National Library of Medicine — Sudden Cardiac Arrest: MedlinePlus Health Topic — MedlinePlus, National Institutes of Health, 2026 — medlineplus.gov
- Mayo Clinic Staff — Sudden cardiac arrest: Symptoms and causes — Mayo Clinic, 2024 — mayoclinic.org
Weiterführende Literatur
- Herzinsuffizienz: Symptome, Ursachen und Behandlungsmethoden
- Lab Test Interpretation Overview
- AI-Powered Blood Test Analysis
- Frequently Asked Questions About BloodSense
- Regular Rate and Rhythm (RRR): What It Means on Your Exam
A cardiac arrest event like PEA often prompts a broader look at cardiovascular health once someone is stabilized, and lab results play a real role in that process. Blood tests such as troponin (a marker of heart muscle strain or injury), a basic metabolic panel that checks electrolytes like potassium and calcium, and arterial blood gases help clinicians identify some of the very reversible causes discussed above. Understanding what these values mean, rather than seeing only numbers and reference ranges, can make follow-up appointments and cardiology visits easier to follow for patients and family members alike.
