Table 2.

Study characteristics.

Study	Study type	Country	Study methods
Dhital et al. (2020)	Observational prospective study	Nepal	High- and low-voltage electrical injury patients on attendance to ED received an initial ECG, then admitted to a cardiac unit for 48 hours. All patients received 1500 ml of intravenous 0.9% saline fluids.
Searle et al. (2013)	Retrospective analysis	Germany	Review of adult and paediatric patients with high-low voltage electrical injuries with a main focus of the evaluation of delayed arrhythmias. All patients had a standardised period of 12 hours cardiac monitoring.
Blackwell & Hayllar (2002)	Prospective observational study	Australia	The study focused on low-voltage electrical injuries and admitted all patients for a period of 6 hours of cardiac monitoring. Any persistent arrhythmias patient were admitted or if ‘normal’ the patient was discharged.
Warentis et al. (2020)	Retrospective analysis	Germany/Austria	High- and low-voltage electrical injuries were reviewed in attendance to two ED units. The study admitted the patients to examine not only the ECG findings but also the associated symptoms and injury characteristics.
Ahmed et al. (2021)	Retrospective chart review	Norway	All adult patients with both high- and low-voltage electrical injuries were examined with a focus on the ECG features, safety of discharge and the overall 30-day mortality.
Akkas et al. (2012)	Retrospective chart review	Turkey	Examination of high- and low-voltage electrical injury patients attending an ED. The data also included patient demographics and time from injury to ECG, however the study had no standardised period of cardiac monitoring.
Arrowsmith et al. (1997)	Retrospective review	United Kingdom	Examination of electrical injury patients from a UK burns unit and the presenting ECG features. Most patients were monitored for a period of 24 hours.

ED: emergency department; ECG: electrocardiogram.