Pulseless electrical activity (PEA) refers to a medical condition in which the electrical activity or rhythm of a person's heart is relatively normal, but the mechanical pumping action of the heart is unresponsive. This lack of response results in cardiac arrest. A patient with PEA has no pulse, is unconscious, is in respiratory arrest, and therefore is clinically dead.
PEA is one of the heart rhythms, along with asystole, that is not electrocutable with a defibrillator such as the automated external defibrillator (AED), because defibrillation is useless. The electrical activity is already intact with the pulseless electrical activity, so there is no electrical chaos that can be remedied by defibrillators. This is the reason why automatic AEDs will not deliver a shock to the patient and semi-automatic AEDs will not advise delivering a shock in such a case. Although normal electrical rhythm is vital to preventing cardiac arrest, the importance of the heart muscle cannot be overstated. Electrical activity and the heart muscle must work together to produce a normal heartbeat.
The causes of pulseless electrical activity are almost always related to the patient who has a severe and terminally ill heart, which can be caused by a number of health problems, including cancer. About four out of 10 cardiac arrest patients suffer from one of the non-shake rhythms, either asystole or PEA. Although an AED is useless and there is little hope of resuscitating the patient, healthcare providers, particularly emergency medical technicians (EMTs) and paramedics, turn to cardiopulmonary resuscitation (CPR) on the way to a medical facility. where care can be transferred to a doctor, who can pronounce death.
Performing CPR is also all that a lay person can do for someone in cardiac arrest caused by pulseless electrical activity until the arrival of emergency medical services (EMS). The only time CPR should not be performed is if the person has a do-not-resuscitate (DNR) order, which is a legal document that lay people and healthcare providers must adhere to. If an AED is not used or available to analyze the heart rhythm of someone in cardiac arrest, there is no way to know if the arrest was caused by pulseless electrical activity or some other rhythm that may or may not be electrocutable. That is why it is important to perform CPR in the absence of a pulse.