Effectiveness of implanted cardiac rhythm recorders with electrocardiographic monitoring for detecting arrhythmias in peripartum cardiomyopathy (PPCM)

Abstract

Introduction: Peripartum cardiomyopathy (PPCM) is a form of dilated cardiomyopathy that occurs within the last months of pregnancy or up to 5 months postpartum. Previous studies have shown that up to 30% of deaths in PPCM are related to sudden cardiac death (SCD). However, little is known about the burden of arrythmias in PPCM and their contribution to SCD. Purpose: We aimed to compare implantable loop recorder (ILR) plus 24-hour Holter monitoring to 24h Holter monitoring alone to assess its utility in the detection of arrhythmias in PPCM. Methods: In this single-centre, prospective clinical trial, 20 consecutive patients with PPCM were randomized to either standard care (SC cohort: ECG & 24-hour Holter) or SC plus ILR (SC-ILR cohort: ECG, 24-hour Holter, ILR). Follow-up included the first six months after ILR implantation. Results: The median age of this cohort was 31.7 years with a parity of 2 (IQR 1-4). They presented with a median left ventricular ejection fraction (LVEF) of 28% (IQR 24-35) and LVEDD of 60mm (IQR 55-66). The 12-lead ECG recorded sinus tachycardia in half of the patients, with median heart rate of 90bpm (IQR 79-106) compared to 94.5bpm (IQR 85-99) on 24h-Holter-monitoring. The median QTc-interval was 464ms (IQR 424-494). Ambulatory ECG monitoring detected major arrhythmias in three women (one in SC cohort, two in SC-ILR cohort). One patient (5%) died shortly after ILR implantation. Her ILR detected sinus arrest with an escape rhythm that failed and resulted in an out of hospital cardiac arrest. Non-sustained ventricular tachycardia (nsVT) occurred in two women (10%), one of which was detected by Holter monitoring and the other on ILR. Both women presented with acute heart failure with severely impaired systolic function (LVEF 12% and 21% respectively). One of these patients had persistent LV systolic dysfunction despite optimal medical therapy and received an implantable cardioverter-defibrillator (ICD). The other patient had intractable heart failure requiring recurrent intensive-care treatment and underwent heart transplantation. There was no atrial fibrillation or atrioventricular block detected in any patient by ECG, Holter or ILR monitoring throughout the study period. Conclusion: This study on ambulatory ECG monitoring in PPCM showed a high prevalence of potentially fatal arrhythmias, which occurred predominantly in the acute phase of the disease. Both Holter and ILR had a direct influence on clinical decision making.