G71 A Review of 24-Hour Ambulatory Holter Electrocardiography

Background The 24-hour ECG is being widely used by paediatricians and paediatric cardiologists to assess children who present with palpitations or other cardiac symptoms. It is also used for children who are known to have an arrhythmia or a cardiac condition, have a family history of serious arrhythmia or suffer from a metabolic disease which can affect their heart. Aims To review the effectiveness of 24-hour ECG in capturing arrhythmias in children. Methods This was a retrospective review of the 24-hour ECG reports between January 2009 and January 2012. The patients were identified from the cardiology database and the reports were accessed via the electronic medical record system of our hospital. Results Over this 3 year period, 178 Holter ECGs were performed. That included 72 female and 106 male patients. The age range was from 4 days to 16 years, with most Holters performed between 1 month to 2 years of age (27%). Most patients (90%) had an ambulatory ECG which lasted for 24 hours, while on 9 occasions it lasted for 48 hours and on 8 occasions for 72 hours. The indications for requesting this investigation were divided into 5 categories: known arrhythmia, known cardiac disease, non-specific palpitations (including chest pain, shortness of breath and ‘funny turns’), family history of prolonged QTc and SUDS and screening due to metabolic disease (Fabry’s). 34 patients (19%) were on medication at the time of the Holter ECG, one had an implanted defibrillator and another one had a pacemaker. In total, significant abnormalities were found in 29 (16%) patients, including SVT, second degree heart block and frequent sinus pauses. Quite importantly, abnormalities were not detected amongst the patients who were being investigated for non-specific palpitations. Of note, 10 such patients experienced symptoms during their 24-hour ECG study; in all cases the recorded rhythm was sinus rhythm. Conclusion In this study, the 24 hour ECG did not reveal any rhythm abnormalities in the patients being investigated for non-specific palpitations and other associated symptoms. However, it demonstrated important abnormalities in patients under follow-up for known arrhythmia, heart disease or relevant family history.