Screening for Life-Threatening Arrhythmia in Asymptomatic Patients After Paediatric Cardiac Surgery: A Single-Centre Retrospective Analysis of 790 Pre-hospital-discharge 24-h Holter Electocardiogram Recordings.

Severe arrhythmias may occur early after open heart surgery. Because younger patients do not usually show any specific symptoms, presently Holter monitoring is routinely performed for 24 h predischarge at our centre to prevent adverse outcomes. It is unknown whether this test is truly justified in this patient population. Retrospective single-centre analysis of all consecutive patients younger than 19 years old after open heart surgery 2013-2019 who underwent routine Holter monitoring before hospital discharge. Patients with permanent pacemakers and patients who died during this hospital stay were excluded. The cohort was divided into two groups depending on whether severe arrhythmia occurred or not. The study includes 790 Holter recordings from 666 patients with a median age of 0.5 years (IQR 0.23-3.08), performed at a median time of 8 days (IQR 6-15) postoperatively. Postoperative arrhythmia was detected in 554 of 790 24-h Holter recordings (70%); in 47 of 790 (6%), this arrhythmia was classified as severe. The most common severe arrhythmias were premature ventricular contractions (n = 26/47) and long pauses (n = 14/47). A longer aortic cross-clamp time (mean 94.5 (SD ± 53.0) versus 68.1 (SD ± 51.9) min, p = 0.001) was associated with the occurrence of severe postoperative arrhythmia. Severe arrhythmias are rare in predischarge assessments after open heart surgery in children. In current postoperative monitoring at our centre, the diagnostic yield of ECG Holter monitoring for 24 h is too low to justify routine screening in all paediatric patients after open heart surgery.