Extrasystoles on 24-h Holter Monitoring During the First Year of Life.

Aim: To assess the natural course of extrasystoles and their association with tachyarrhythmias on 24-h Holter monitoring during the first year of life.

Methods: A retrospective chart review was performed among newborns referred for 24-h Holter monitoring at Tampere University Hospital from 2011 to 2017. Children with more than 1% extrasystoles on the initial Holter recording were included.

Results: In total, 75 children and 290 Holter recordings were included. Forty-seven (63%) children were followed up due to atrial premature contractions (APCs) and 28 (37%) children were followed up due to ventricular premature contractions (VPCs). The amount of extrasystoles peaked during the first 14 days and decreased significantly during the first 2 months. However, in one-third of the children, extrasystoles increased between recordings. Extrasystoles disappeared during the first year among 92% of children with APCs and 78% of children with VPCs. Short supraventricular or ventricular tachycardias were found in 17 (23%) children's recordings. A higher percentage of extrasystoles was associated with tachyarrhythmias.

Conclusion: The results support the prevailing understanding regarding the favourable prognosis of extrasystoles in newborns. Serial Holter monitoring may be advisable during the newborn period for infants with frequent extrasystoles, as some may be susceptible to tachyarrhythmias.