electromechanical dissociation
Also written as: PEA — pulseless electrical activity
A cardiac arrest rhythm characterized by organized electrical activity on ECG but absence of effective mechanical contraction and pulse.
Full Definition
Electromechanical dissociation, also known as pulseless electrical activity (PEA), represents a form of cardiac arrest where the heart maintains organized electrical depolarization but fails to generate adequate mechanical contraction to produce a detectable pulse or blood pressure. This condition can result from severe hypovolemia, massive pulmonary embolism, tension pneumothorax, cardiac tamponade, severe acidosis, hyperkalemia, or massive myocardial infarction. The ECG may show various rhythms including sinus rhythm, atrial fibrillation, or ventricular rhythms, but all are characterized by the absence of effective cardiac output. Treatment focuses on identifying and correcting reversible causes while providing cardiopulmonary resuscitation.
Usage
Usage note: PEA is the preferred modern terminology over electromechanical dissociation.
In Context
- "The patient presented in cardiac arrest with electromechanical dissociation showing sinus rhythm at 80 bpm but no palpable pulse." — Emergency department resuscitation note
- "ACLS protocols for electromechanical dissociation were initiated while searching for reversible causes including pulmonary embolism." — Code blue summary