Effectiveness of implanted cardiac rhythm recorders with electrocardiographic monitoring for detecting arrhythmias in peripartum cardiomyopathy (PPCM)
Authors: Hoevelmann J , Viljoen C A , Chin A , Briton O , Sliwa K 
Published: October 2021

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 (figure 1A) 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 (figure 1B, 1C). 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. One patient had sinus arrest and asystole detected by ILR as the terminal arrhythmia. Both Holter monitoring and ILR played an important role in ventricular arrhythmia detection, which in two cases had a direct influence on clinical decision making. ILR is more effective than 24-hour Holter monitoring in paroxysmal arrhythmia detection because of extended monitoring.

Funding Acknowledgement
Type of funding sources: Private company. Main funding source(s): Medtronic South Africa Ambulatory ECG monitoring in PPCM