Symptomatic atrial bigeminy masquerading as congenital complete heart block

Area of Science:

• Pediatric Cardiology
• Electrophysiology
• Neonatal Medicine

Background:

• Symptomatic bradycardia in newborns can be challenging to manage.
• Complete atrioventricular block is a serious condition requiring intervention.
• Pharmacological management is an alternative to invasive procedures.

Purpose of the Study:

• To report a case of neonatal bradycardia initially diagnosed as complete atrioventricular block.
• To describe the successful treatment of a complex arrhythmia with flecainide.
• To highlight the potential for non-invasive management of certain neonatal cardiac conditions.

Main Methods:

• A newborn male presented with symptomatic bradycardia.
• Initial diagnosis of complete atrioventricular block led to isoproterenol infusion and pacemaker planning.
• Serial electrocardiograms and Holter monitoring were performed.
• Flecainide was administered for treatment.

Main Results:

• Repeat investigations revealed near continuous blocked atrial bigeminy with aberrantly conducted premature atrial contractions, not complete atrioventricular block.
• Flecainide administration resulted in the restoration of normal sinus rhythm.
• Pacemaker implantation was successfully avoided.

Conclusions:

• Flecainide can be an effective treatment for specific types of neonatal supraventricular tachycardias presenting as bradycardia.
• Accurate diagnosis through serial monitoring is crucial in managing neonatal arrhythmias.
• Non-invasive pharmacological therapy can prevent the need for permanent pacemakers in select cases.