Bradycardia: Quick Study Guide to Symptoms & Treatment

Bradycardia is an abnormally slow heart rate. It can occur normally in healthy individuals during sleep as well as in athletes who have a higher than average level of physical fitness.

According to the ACLS Provider Manual, symptomatic bradycardia exists when any or all of the following symptoms are present:

  • Heart rate <60 bpm
  • Distressed respiration that may progress to respiratory failure
  • Decreased systolic blood pressure
  • Increased capillary refill time
  • Pale and cool skin
  • Fatigue or dizziness
  • Diminished or absent peripheral pulses


Identifying Bradycardia on an ECG Strip

On an ECG strip where bradycardia is indicated, the P wave and QRS complex are variable. The P wave and QRS complex may not be associated with each other, also known as AV Dissociation.


ACLS Bradycardia Algorithm

Once bradycardia is identified, treatment should begin immediately while also looking for the underlying cause. Possible underlying causes of bradycardia include the Hs and Ts:

  • Hypoxia
  • Hydrogen ion (acidosis)
  • Hyperkalemia
  • Hypothermia
  • Heart block
  • Toxins
  • Trauma

If necessary, establish an airway to assist with breathing. Monitor the patient’s heart rate, heart rhythm and blood pressure. If the patient is in hypotension or shock, establish an IV or IO access and administer atropine every 3 to 5 minutes in 0.5 mg doses up to a maximum of 3 mg.

If the patient is not in hypotension or shock, continue monitoring their vital signs and call for a consult.

For more information on bradycardia and to review the ACLS bradycardia algorithm, check the ACLS Provider Manual. You can purchase the manual here or receive it as part of your tuition when you register for ACLS certification.