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Wolff-Parkinson-White syndrome in the neonate
Insights
Half of infants with paroxysmal supraventricular tachycardia show Wolff-Parkinson-White conduction patterns, suggesting immature bypass pathways. These pathways often resolve as the neonatal heart matures, but extended surveillance is recommended.
Area of Science:
- Pediatric Cardiology
- Electrophysiology
- Neonatal Medicine
Background:
- Paroxysmal supraventricular tachycardia (PSVT) is a common arrhythmia in neonates.
- Wolff-Parkinson-White (WPW) conduction patterns are observed in some infants with PSVT.
- Neonatal cardiac electrophysiology is influenced by autonomic innervation.
Purpose of the Study:
- To investigate the prevalence and characteristics of electrocardiographic patterns suggestive of bypass tracts in neonates with PSVT.
- To explore the role of immature bypass pathways and autonomic innervation in neonatal PSVT.
- To understand the natural resolution of WPW patterns and PSVT in infants.
Main Methods:
- Retrospective analysis of electrocardiographic (ECG) findings in 16 infants diagnosed with PSVT during the neonatal period.
- Correlation of ECG patterns with clinical presentation and potential electrophysiological mechanisms.
- Review of literature regarding neonatal cardiac maturation and autonomic influences.
Main Results:
- Fifty percent of infants with neonatal PSVT exhibited ECG patterns consistent with Wolff-Parkinson-White conduction, type A.
- Electrically active bypass tracts, potentially Kent pathways, are implicated in neonatal PSVT.
- Enhanced pathway activity in neonates may be linked to predominant cholinergic innervation.
- Resolution of WPW patterns and PSVT is often associated with cardiac maturation and changing autonomic balance.
Conclusions:
- Neonatal PSVT is frequently associated with immature bypass pathways, evidenced by WPW patterns.
- Cardiac maturation, altered autonomic innervation, and decreased cholinergic dominance contribute to arrhythmia resolution.
- Incomplete maturation can lead to persistent or intermittently active bypass fibers.
- Extended surveillance is crucial for infants presenting with neonatal PSVT and WPW patterns.
Abstract:
Of 16 infants who presented with paroxysmal supraventricular tachycardia in the neonatal period, 50 percent had an electrocardiographic pattern consistent with Wolff-Parkinson-White conduction, type A. It is suggested that infants have bypass pathways similar to or identical with a Kent pathway as part of normal maturation. Infants with paroxysmal supraventricular tachycardia have electrically active bypass tracts but these are documented in only about one half of the patients because of the short duration of recordings or because of concealment (the bypass tract conducts only in retrograde fashion). The activity of these pathways is enhanced by the predominant cholinergic innervation of the neonatal heart. Resolution of the arrhythmias and the Wolff-Parkinson-White pattern in most patients occurs because of anatomic maturation of the conduction tissue, development of adrenergic innervation and a decrease in cholinergic dominance. In some children, maturation is incomplete and the bypass fibers remain quiescent or become active under certain circumstances such as those associated with increased autonomic discharge. Extended surveillance is recommended for all infants who present with paroxysmal supraventricular tachycardia and the Wolff-Parkinson-White pattern.