Cardiology
Congenital heart disease, arrhythmias and murmurs.
Use as a study guide only. These notes are part of a free open-access medical education (FOAMed) project and may contain errors or outdated information. Always verify against current guidelines (e.g. eTG, RACGP, local health district policies) and reputable sources before applying anything to patient care. See the full disclaimer.
Clinical pearls & learnings
Tips and tricks collected over the years — a living list that grows with every rotation. Use as a study guide only and check current guidelines before acting on anything.
Arrhythmias
Supraventricular tachycardia
The giveaway is a fast, unvarying rate with no beat-to-beat variability — unlike sinus tachycardia, which varies with stimulation and settles with treatment of the cause.
- Stable: vagal manoeuvres — modified Valsalva, or ice/cold to the face in infants
- Stable, vagal failed: adenosine by rapid push with a flush, at escalating doses
- Unstable (or no IV access): synchronised DC cardioversion at 1 J/kg, then 2 J/kg
- Refractory: seek expert help — amiodarone under cardiology guidance
Escalation depends on whether the child is stable
Cardioversion for SVT must be synchronised. The 1 J/kg then 2 J/kg figures are for synchronised cardioversion — defibrillation for a shockable arrest rhythm (VF/pulseless VT) is 4 J/kg. Do not mix the two up.
Bradycardia
| Cause | Approach |
|---|---|
| Hypoxia — the commonest cause in children | Oxygenate and ventilate first. Bradycardia in a child is a pre-arrest sign until proven otherwise |
| Vagal stimulation (suctioning, laryngoscopy, NG insertion) | Stop the trigger, correct hypoxia, treat pain and distress; atropine 20 mcg/kg if significant |
| Haemodynamically unstable sinus bradycardia | Atropine, then adrenaline |
| Complete heart block | Fluids and atropine, then transcutaneous pacing, bridging to transvenous pacing and a permanent pacemaker |
Start CPR if the heart rate is under 60 with poor perfusion despite adequate oxygenation and ventilation.
Duct-dependent lesions
Duct-dependent congenital heart lesions
- Suspect in the collapsed neonate in the first weeks of life as the duct closes.
- Do not fluid overload — check for hepatomegaly as a sign of heart failure, and note that failure to improve after a bolus (with new wheeze, crackles and worsening tachypnoea from flash pulmonary oedema) is a major clue.
- Start a prostaglandin (PGE1) infusion early to reopen the duct, ± inotropes. Be ready for apnoea, a known prostaglandin side effect.