When the heart rate goes below 50 beats per minute, we can label it as bradycardia.
Bradycardia can be a sinus bradycardia or one of the heart blocks.
Regardless of the types, the management is similar.
Not every bradycardia needs to be treated.
Some people have low heart rates all the time without any symptoms, which is called physiologic bradycardia (Eg: athletes / high endurance exercise / during sleep).
Symptomatic Vs Asymptomatic bradycardia
On receiving a patient, you can proceed in your regular fashion of speaking to the patient and checking vitals on a bed.
Give supplemental oxygen if saturations are below 94% on room air.
Take a 12 lead ECG if time permits. Gain IV – Intravenous access (or Intra-osseous if IV is not possible)
When you see a heart rate below 50 per minute on the monitor or via pulse check, first thing to do is to check if the low heart rate is causing any symptoms to the patient. Use the following signs to differentiate (Similar signs are used in tachycardia as well to differentiate stable and unstable bradycardia.)
|1. Ischemic chest pain||Chest pain or upper abdominal pain.|
|2. Signs of heart failure||Left heart failure: Crackles in lungs|
Right: Pedal edema, facial puffiness, ascites.
|3. Hypotension||Sweating, giddiness|
|4. Signs of shock||Cold clammy peripheries, sweating, bluish fingers or oral mucosa|
|5. Altered mental status||Drowsiness, Disorientation, or coma.|
If the patient does not have any of the 5 signs listed above, simply keep monitoring the patient and give appropriate referral.
If the patient happens to have even one of the 5 listed signs, label it as symptomatic bradycardia and start managing the case as per ACLS guidelines.
First, try to improve the heart rate with Atropine. You can give 0.5mg IV stat, followed by flush, which may be repeated every 3-5 minutes up to 6 doses (that is 3mg max).
If dopamine is ineffective, you can try trans-cutaneous pacing if available.
Start an infusion of Dopamine at 2-20 micro grams (mcg) per kg per minute.
Start an infusion of Epinephrine at 2-10 micro grams (mcg) per minute.
Consult the expert (cardiologist) for trans-venous pacing if your interventions are ineffective.