Interpreting the Need for Implantable Loop Recorder Monitoring in Pregnant Women at High Risk of Arrhythmias

To the Editor We congratulate Sliwa et al¹ for their excellent analysis on the use of implantable loop recorders (ILRs) in addition to 24-hour Holter electrocardiography to improve the detection of arrhythmias in pregnant women with cardiovascular disease compared with 24-hour Holter electrocardiography alone. We believe these findings to be pertinent, as a 2019 study by Moulig et al² observed 66 patients with peripartum cardiomyopathy over 5 years and found that 17% had arrhythmias, including paroxysmal supraventricular tachycardia, ventricular tachycardia, or ventricular fibrillation. It should be noted the large number of arrhythmias found in this population may be because 9 patients had wearable cardioverter-defibrillators inserted at diagnosis. Of these patients, 8 also had permanent implantable cardioverter-defibrillators inserted.² These data show that patients with peripartum cardiomyopathy remain at high risk of arrhythmias for prolonged periods and could see considerable benefit from monitoring as described by Sliwa et al.¹