I44.1/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 in MORPHINE, IV (i.e. monitoring for response and toxicity).
AV nodal block with narrow QRS complex escape rhythm only:
- Atropine, IV bolus, 0.6–1.2 mg.
- May be repeated as needed until a 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
For resuscitation of asystole in combination with CPR:
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
- All cases with a heart rate <40 bpm after resuscitation and stabilisation.
- 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.
A permanent pacemaker is the definitive form of treatment. These are only available in tertiary institutions. Refer all symptomatic patients with significant bradyarrhthmias for evaluation.