Dry textile electrode for ambulatory monitoring after catheter ablation of atrial fibrillation: A pilot study of simultaneous comparison to the Holter electrocardiogram

Abstract

Background: Holter electrocardiogram (ECG) is the gold standard for ambulatory monitoring of atrial fibrillation (AF) but it is insufficient because of its limited recording time. Although several consumer ECG devices provide longer recording time, they generally do not undergo the regulatory process for medical use. Furthermore, current medical-grade devices for longer ECG monitoring are not continuous or too invasive for AF monitoring. A wearable ECG with a medical-grade dry textile electrode is a promising technology to remedy this limitation. This pilot study aimed to simultaneously compare the wearable and Holter ECGs for ambulatory monitoring in a clinical setting. Methods: This prospective observational study enrolled 18 patients who underwent AF ablation. One day after AF ablation, ambulatory ECG was obtained for three hours simultaneously using both the wearable and Holter ECG devices. Automatic ECG interpretations between devices were compared with correlation and agreement analyses. Results: Simultaneous ECG monitoring demonstrated a comparable analysis time and total heart beats between the two devices. Almost complete correlation and agreement were also demonstrated in all clinically relevant testing aspects except in R-wave amplitude (r = 0.743, p < .001). AF was detected in three patients. AF duration was the same in both ECG devices in two patients with continuous AF. In the remaining patient with intermittent AF, AF duration was shortened by 0.6% with the wearable ECG as compared to that with the Holter ECG. Conclusions: Simultaneous ECG comparison revealed a high consistency between the wearable and Holter ECG devices. The results of this study warrant further clinical studies for long-term monitoring of ambulatory ECG after AF ablation.

Keywords: ambulatory monitoring; atrial fibrillation; catheter ablation; textile electrode; wearable electrocardiogram.

Figure 1.. Simultaneous positioning of textile and gel electrodes.

Bipolar electrodes for CC5 lead were positioned to avoid interference between textile and gel electrodes.

Figure 2.. Simultaneous tracing from wearable ECG (A) and Holter ECG (B).

Electrodes were positioned to compose a bipolar lead CC5 in both ECG devices. ECG, electrocardiogram; HR, heart rate.

Figure 3.. Correlation and Bland-Altman analysis between wearable and Holter ECGs.

The scatterplot diagrams (A–D) illustrate correlation analysis with Pearson’s coefficient (r) and P values. The Bland-Altman plots (E–H) show a bias (solid line) with 95% limits of agreement (dotted line). Each dot represents paired values derived from all patients. An open circle indicates a patient with skin-electrode contact failure. ECG, electrocardiogram.

Figure 4.. Simultaneous tracings of automatic interpretation from wearable ECG (A) and Holter ECG (B).

Time in atrial fibrillation was indicated by the blue line. Most noise signals on wearable ECG were labeled as normal QRS complexes on Holter ECG. The gray signal with asterisk indicates noise; black signal, normal QRS complex; blue signal, atrial premature complex; pink signal, ventricular premature complex. ECG, electrocardiogram.