Sliwa K, Azibani F, Johnson MR, et al. - A single-center, prospective randomized clinical trial was designed to correlate implantable loop recorder (ILR) plus 24-hour Holter electrocardiographic (ECG) monitoring with standard 24-hour Holter ECG monitoring alone in terms of acceptability, ability to distinguish significant arrhythmias, and effect on management and pregnancy outcome in women who were symptomatic or at high risk of arrhythmia because of underlying structural heart disease. A total of 40 consecutive individuals from the Cardiac Disease and Maternity Clinic at Groote Schuur Hospital in Cape Town, South Africa were included. This study enrolled pregnant individuals with symptoms of arrhythmia and/or structural heart disease at risk of arrhythmia. Individuals were assigned randomly to standard care (SC; 24-hour Holter ECG monitoring [n = 20]) or standard care plus ILR (SC-ILR; 24-hour Holter ECG monitoring plus ILR [n = 20]). In detecting arrhythmias, the ILR was better than 24-hour Holter monitoring, which led to a change in management for a significant proportion of individuals. Evidence indicated that, for pregnant women, ILR may be useful at risk of arrhythmia.