Antiarrhythmic therapy for narrow QRS supraventricular tachyarrhythmias in newborns and infants in the first year of life: Potent tools to be handled with care

Figures

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  Fig. 1. Transesophageal electrophysiologic study. Atrioventricular reentrant tachycardia (AVRT) with transient bundle branch aberrancy. The increase in tachycardia cycle length (TCL) and ventriculoatrial (VA) interval during aberrancy strongly suggested the diagnosis of AVRT over a concealed accessory pathway located on the same side of the bundle branch block.

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  Fig. 2. Transesophageal electrophysiologic study. Atrial pacing induced atrioventricular nodal reentrant tachycardia (AVNRT).

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  Fig. 3. Junctional ectopic tachycardia during transesophageal electrophysiologic study. Narrow QRS tachycardia with VA dissociation.

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  Fig. 4. Ectopic atrial tachycardia on surface ECG. Evidence of P waves superimposed on the T waves with a long RP interval.

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  Fig. 5. Signs of flecainide toxicity on surface ECG.

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  Fig. 6. Schematic flow chart summarizing acute management and oral prophylactic antiarrhythmic treatment for narrow QRS supraventricular tachycardia in newborns and infants. The choice of the pharmacological regimen varies widely based on the type of arrhythmia, as well as personal preference and experience.