Internal Medicine

Pulseless electrical activity (PEA)

Clinical condition characterized by unresponsiveness and impalpable pulse in the presence of sufficient electrical discharge.

Clinical condition characterized by unresponsiveness and impalpable pulse in the presence of sufficient electrical discharge.

  • Also known as electromechanical dissociation
  • Accounts for ~20% of sudden cardiac deaths (SCD) outside of the hospital setting
  • Due to lack of/insufficient electrical activity required for contraction:
    • Pseudo-PEA: Ventricular contractions + detectable pressures in aorta
    • True PEA: Cardiac contractions lacking in presence of coordinated electrical impulses


Primary/cardiac causes:

Due to depletion of myocardial energy reserves

Secondary/noncardiac causes:

  • 5 Hs
    • Hypovolemia (M/C cause)
    • Hypoxia (#2 M/C cause)
    • Hydrogen ion (acidosis)
    • Hypo/hyperkalemia
    • Hypothermia
  • 5 Ts
    • Tension pneumothorax
    • Trauma
    • Tamponade
    • Thrombosis, pulmonary
    • Thrombosis, coronary



  • Organised/semi-organised electrical activity; as opposed to asystole (flatline) or to the disorganised electrical activity of either ventricular fibrillation or ventricular tachycardia
Pulseless electrical activity, it is possible to observe by invasive blood pressure (red) the transition from a normal mechanical activity of the heart, which progressively changes in rhythm and contractile quality to asystolia, even in the presence of normal electrical activity (green), also confirmed by the pulse oximeter detection even if with artifacts (blue) | A7N8X – CC BY-SA 4.0,

Differential diagnosis:

  • Accelerated idioventricular rhythm
  • Acidosis
  • Cardiac tamponade
  • Drug overdose
  • Hypokalemia
  • Hypothermia
  • Hypovolemia
  • Hypoxemia
  • Myocardial ischemia
  • Pulmonary embolism
  • Syncope
  • Tension pneumothorax
  • Ventricular fibrillation


Cardiopulmonary resuscitation (Cardiac resuscitation guidelines (ACLS/BCLS)):

To maintain cardiac output until the PEA can be corrected and immediate management of any secondary cause (if present)
  • Decompression of pneumothorax, pericardial drain for tamponade, fluids infusion, correction of body temperature, administration of thrombolytics, or surgical embolectomy for pulmonary embolus.

Drug management:

Administered with appropriate CPR techniques
  • Epinephrine (1 mg IV/IO every 3-5 min during PEA arrest) (mainstay drug therapy)
  • Bradycardia + hypotension: Atropine (1 mg IV q3-5 min, up to 3 doses)
  • Severe, systemic acidosis, hyperkalemia, or tricarboxylic acid overdose: NaHCO3 (1 mEq/kg)
  • Defibrillators (cannot be used as problem lies in response of myocardial tissue to electrical impulses)

Surgical management:

  • Pericardial drainage and emergent surgery

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