Incidence of non-benign arrhythmia in neonatal intensive care unit: 18 years experience from a single center.

Background: Non-benign arrhythmias, which require urgent recognition and care in neonatal intensive care unit (NICU) settings, are rare but can severely impact neonates. We aimed to clarify the epidemiology and characteristics of non-benign arrhythmias and their influence on neonates. Methods: This single-center retrospective study included patients admitted to the NICU at Kurashiki Central Hospital between January 2001 and December 2019. Only patients with structurally normal hearts were included. The use of direct cardioversion (DC), antiarrhythmic agents, and the presence of risk factors was reviewed from medical records. Results: Of the 8082 admissions, 2919 patients (36.1%) were low birth weight infants (LBWI) weighing less than 1500 g. There were 23 patients with arrhythmias (nine of them were LBWIs) with an incidence of 0.28%. There were 16 patients with tachyarrhythmia (eight supraventricular tachycardia [SVT] cases, three atrial flutters [AFL] cases, three ventricular tachycardia cases, two junctional ectopic tachycardia cases), and seven with bradyarrhythmia (all with complete atrioventricular [AV] block). For tachyarrhythmia cases, seven patients required DC, and eight were on antiarrhythmic agents at the time of discharge. Two patients (28.5%) with complete AV block required pacemaker implantation before discharge. The treatment strategy was dependent on the type of arrhythmia. All patients were discharged without significant morbidities. Conclusions: The incidence of non-benign arrhythmias was as low as 0.28%. Arrhythmias can be managed successfully in neonates, yet risk factors related to mortality warrant further study.