Cardiovascular

Heart Block (2nd or 3rd Degree AV Block) Treatment

ICD 10 Code = I44.1 or I44.2

Description

The majority of cases occur in patients >60 years of age and are idiopathic, with an excellent long-term prognosis, provided a permanent pacemaker is implanted.

Acute, reversible AV block commonly complicates inferior myocardial infarction.

Heart block may also be induced by metabolic and electrolyte disturbances, as well as by certain medicines.

General Measures

Emergency cardio-pulmonary resuscitation (if necessary).

External pacemaker should be available in all secondary hospitals and must be preceded by appropriate analgesia.

Medicine Treatment

Analgesia if external pacemaker

  • Morphine, IM, 10-15 mg 3-6 hourly.

Apply relevant precautions as indicated (i.e. monitoring for response and toxicity).

Morphine, IV, to a maximum dose of 10 mg. Give 3–5 mg as a single dose then further boluses at intervals of 5–10 minutes and monitor all vitals closely.

Dilute 10 mg up to 10 mL with sodium chloride 0.9%. Repeat after 4 hours if necessary.

Monitor response to pain and effects on respiration and blood pressure. Onset 5–10 minutes. Duration of action 4-5 hours.

AV Nodal Block with Narrow QRS Complex Escape Rhythm Only

Atropine, IV bolus, 0.6-1.2 mg.

  • May be repeated as needed until pacemaker is inserted.
  • Use in patients with inferior myocardial infarct and hypotension and second degree AV block, if symptomatic.
  • It is temporary treatment of complete AV block before referral (urgently) for pacemaker.

OR

Resuscitation of Asystole in Combination with CPR

ICD 10 codes = I46.0-1/I46.9+(I44.1-2).

Adrenaline (epinephrine) 1:10 000, slow IV, 5 mL (0.5 mg).

  • Used as temporary treatment of complete heart block when other medicines are not effective.

Referral

  1. All cases with a heart rate <40 bpm after resuscitation and stabilisation.
  2. All cases of 2nd or 3rd degree AV block, whether or not myocardial infarct or other reversible cause is suspected, and whether or not the patient is thought to be symptomatic.

Sinus Bradycardia

ICD 10 code = R00.1

Description

This rhythm does not require treatment, unless it is causing symptoms, i.e. syncope, dizziness, tiredness and poor effort tolerance.

Sinus bradycardia <50 bpm or sinus arrest with slow escape rhythm, accompanied by hypotension, strongly suggest a treatable underlying cause such as:

  • acute inferior myocardial infarct
  • hyperkalaemia, especially if wide QRS and/or peaked T waves,
  • medicines, especially combination of verapamil and ß-blocker or digoxin,
  • hypothermia,
  • hypoxia, or
  • Hypothyroidism.

Treat the cause. Consider atropine if inferior myocardial infarct.

Sinus Arrest (ICD 10 code = I50): refer all cases to cardiologist.

For more information on heart block read here.