PEA & Asystole Algorithm

AHA 2015 ACLS Algorithm for the treatment of Pulseless Electrical Activity (PEA) and Asystole

PEA and Aystole are two “non-shockable” rhythms that can be found in patients in cardiac arrest. Asystole is the absence of electrical activity and PEA is the presence of an organized rhythm but with no pulse or signs of perfusion.

Treatment of PEA and Asystole are based around providing effective CPR and identifying and treating reversible causes also know as the H’s and T’s.

Pulseless electrical activity or PEA refers to a cardiac arrest situation in which a heart rhythm is observed on the ECG that should produce a palpable pulse, but is not. In PEA, there is an organized rhythm but the heart either does not contract or there is insufficient cardiac output to generate a pulse. The above rhythm is just one of many ways PEA can present as an organized rhythm without a pulse.

Asystole is a state of no cardiac electrical activity; hence no contractions of the heart muscle and thus no cardiac output or blood flow. Asystole is easily recognized by it’s “flatline” presentation. It is important to confirm that the asystole is a true flatline and not fine “fine v-fib”, human error or equipment malfunction.  Survival rates in a cardiac arrest patient with asystole are very low.

Perform initial assessment

Perform High Quality CPR with supplemental O2 and attach ECG

If PEA/Asystole

Immediately resume High Quality CPR for 2 minutes and initiate IV/IO
Administer Epinephrine 1mg IV/IO q/3-5 minutes once IV/IO initiated.
Consider advanced airway (ETT, Supraglottic Airway)
Consider Reversible Causes (H’s & T’s)

Continue 2 min cycles and provide subsequent CPR and Rx until:

The monitor and assessment show V-Tach or V-Fib, move to V-Tach/V-Fib algorithm
If the patient attains Return of Spontaneous Circulation (ROSC), provide Post Cardiac Arrest Care
If patient is in asystole and remains so for 2 rounds of epi and a fluid bolus, begin considering terminating resuscitative efforts.


  • Providing high quality CPR with minimal interruptions and identifying/treating reversible causes are key to patient survival.

Reversible Causes

Consider and treat potential reversible causes throughout an arrest or dysrhythmias 

Hypovolemia: S/S - Rapid heart rate and narrow QRS on ECG; other symptoms of low volume TX - Infusion of normal saline or Ringer’s lactate

Hypoxia: S/S -Slow heart rate TX - Airway management and effective oxygenation

Hydrogen Ion Excess (Acidosis): S/S - Low amplitude QRS on the ECGHyperventilation TX - consider sodium bicarbonate bolus

Hypoglycemia: S/S - Bedside glucose testing TX IV bolus of dextrose

HypokalemiaS/S - Flat T waves and appearance of a U wave on the ECG TX - IV Magnesium infusion

HyperkalemiaS/S - Peaked T waves and wide QRS complex TX - Consider calcium chloride, sodium bicarbonate, or an insulin and glucose protocol

Hypothermia: S/S - Typically preceded by exposure to a cold environment; TX - Gradual rewarming

Tension Pneumothorax: S/S -Slow heart rate and narrow QRS complexes on the ECG; difficulty breathing TX -Thoracostomy or needle decompression

Tamponade – CardiacS/S - Rapid heart rate and narrow QRS complexes on the ECG TX Pericardiocentesis

Toxins: S/S - Typically will be seen as a prolonged QT interval on the ECG; may see neurological symptoms TX Based on the specific toxin

Thrombosis (PE)S/S - Rapid heart rate with narrow QRS complexes on the ECG TX Surgical embolectomy or administration of fibrinolytics

Thrombosis (MI): S/S - ECG will be abnormal based on the location of the infarction TX Dependent on extent and age of MI

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