Symptomatic sinus bradycardia in infants with structurally normal hearts.

Area of Science:

• Pediatrics
• Cardiology
• Neurology

Background:

• Infants presenting with syncopal attacks, apneic episodes, or seizures often undergo extensive metabolic and neurologic evaluations.
• Diagnostic workups for these symptoms in infants frequently yield normal results, complicating diagnosis and treatment.
• Identifying the underlying cause of these episodes is crucial for appropriate management and preventing adverse outcomes.

Observation:

• Sixteen infants (6 weeks to 23 months) were assessed for recurrent syncopal attacks, apneic episodes, or combined symptoms.
• Standard metabolic and neurologic investigations were unremarkable in 15 infants; one showed an abnormal electroencephalogram (EEG).
• Cardiac rhythm abnormalities, including severe sinus bradycardia, sinus arrest, and escape rhythms, were identified in four infants.

Findings:

• Four infants diagnosed with significant cardiac arrhythmias required intervention.
• Permanent multiprogrammable pacemakers were successfully implanted in these four infants.
• Follow-up over 6 to 24 months demonstrated complete resolution of symptoms in two infants and marked improvement in two others.

Implications:

• Pacemaker implantation is a viable and effective treatment for selected infants with life-threatening cardiac arrhythmias causing syncope or apnea.
• Early diagnosis and intervention with cardiac pacing can significantly improve outcomes for infants with these conditions.
• This study highlights the importance of considering cardiac etiologies in infants with recurrent unexplained syncopal or apneic events.