Pulseless electrical activity (PEA) is the presence of cardiac
electrical activity with organized or partially organized cardiac
rhythms without a palpable pulse. PEA is formerly known as
electromechanical dissociation (EMD). PEA can present as any
organized or partially organized rhythm on an
electrocardiogram (ECG).
PEA occur due to an event that takes place within the
respiratory, cardiovascular, or gastrointestinal systems of the
body which contributes to insufficient force generated by the
heart following electrical depolarization. This insufficient force
results in a weakened ability of the heart to contract, which
can lead to a worsening cascade of pathophysiological
changes.
• Primary PEA is associated with cardiac causes (such as
cardiac arrest), whereas secondary pulseless electrical
activity is due to noncardiac causes.
• Secondary PEA is due to potential reversible causes, known
as the Hs & Ts.
o H’s: Hypoxia; Hypovolemia; Hypo/hyperkalemia;
Hydrogen ion (acidosis); Hypothermia.
o T’s: Tension pneumothorax; Tamponade; Trauma;
Thrombosis (coronary); Thrombosis (pulmonary)
• Hypoxia and hypovolemia are two of the most common and
potentially reversible causes of PEA.
• Medications may increase susceptibility for the
development of PEA. E.g., patients who use BBs or CCBs are
at an increased risk for PEA because of decreased
contractility of the heart due to altered intracellular
calcium levels.
• Pulmonary Embolus is a major cause of PEA in maternal
health
• Rhythm: vary depending on the underlying rhythm
• Rate: vary depending on the underlying rhythm
• P wave: varies; PEA may occur with and without visible
P waves
• PR interval: normal or prolonged, depending on
underlying rhythm
• QRS Complex: normal or wide, depending on underlying
rhythm
✓ Absence of a palpable pulse
✓ Apnea
✓ Cyanosis
✓ Respiratory acidosis
✓ Hypothermia
✓ Electrolyte imbalance (e.g., hypo- or hyperkalemia)
✓ Blood loss/hemorrhage (resulting in hypovolemia)
✓ Pallor
✓ Hypoxia
✓ Jugular venous distention
✓ Tracheal deviation
Important Note: a pulse that cannot be palpated does not
always indicate PEA⎯ this could also occur due to
abnormalities of the peripheral vascular system
The first step in managing pulseless electrical activity is to begin chest
compressions according to the advanced cardiac life support (ACLS)
protocol followed by administrating epinephrine every 3 to 5 minutes,
while simultaneously looking for any reversible causes.
• CPR:
o Effective CPR should be started, with minimal interruptions
o Administer oxygen
o Attach the defibrillator or cardiac monitor and evaluate the
cardiac rhythm
o Consider establishing an advanced airway and capnography
• Medications
o Epinephrine
▪ For a patient with cardiac arrest and a non-shockable rhythm
such as pulseless electrical activity, administer epinephrine as
early as possible
▪ 1mg IV/IO should be administered, eligible for additional doses
every 3-5 minutes followed by 20 ml of flush
▪ Be sure to administer medications during CPR - do not stop CPR
during medication administration
o Atropine
▪ If the detected rhythm is bradycardia that is associated with
hypotension
▪ Administer 1 mg IV every 3-5 min, up to three doses
• Underlying Causes
Interventions for managing pulseless electrical activity are focused on
tending to the underlying cause of cardiac arrest rather than
converting the cardiac rhythm.
o Caring for the patient with pulseless electrical activity requires
considerations outside of the algorithm
o When assessing the patient, determine if there are any
contributing and reversible underlying causes of the patient’s
clinical condition (H’s and T’s)
o Hypovolemia and hypoxia are two of the most common causes of
pulseless electrical activity that are potentially reversible
o Sodium bicarbonate may be used only in patients with severe,
systemic acidosis, hyperkalemia, or tricarboxylic acid overdose.
The dose is 1 mEq/kg