Scientific article
Open access

High incidence of inappropriate alarms in patients with wearable cardioverter-defibrillators: findings from the swiss WCD registry

Published inJournal of clinical medicine, vol. 10, no. 17, 3811
Publication date2021-08-25
First online date2021-08-25

Background: The wearable cardioverter defibrillator (WCD) uses surface electrodes to detect arrhythmia before initiating a treatment sequence. However, it is also prone to inappropriate detection due to artefacts. Objective: The aim of this study is to assess the alarm burden in patients and its impact on clinical outcomes. Methods: Patients from the nationwide Swiss WCD Registry were included. Clinical characteristics and data were obtained from the WCDs. Arrhythmia recordings ≥30 s in length were analysed and categorized as VT/VF, atrial fibrillation (AF), supraventricular tachycardia (SVT) or artefact. Results: A total of 10653 device alarms were documented in 324 of 456 patients (71.1%) over a mean WCD wear-time of 2.0 ± 1.6 months. Episode duration was 30 s or more in 2996 alarms (28.2%). One hundred and eleven (3.7%) were VT/VF episodes. The remaining recordings were inappropriate detections (2736 (91%) due to artefacts; 117 (3.7%) AF; 48 (1.6%) SVT). Two-hundred and seven patients (45%) had three or more alarms per month. Obesity was significantly associated with three or more alarms per month (p = 0.01, 27.7% vs. 15.9%). High alarm burden was not associated with a lower average daily wear time (20.8 h vs. 20.7 h, p = 0.785) or a decreased implantable cardioverter defibrillator implantation rate after stopping WCD use (48% vs. 47.3%, p = 0.156). Conclusions: In patients using WCDs, alarms emitted by the device and impending inappropriate shocks were frequent and most commonly caused by artefacts. A high alarm burden was associated with obesity but did not lead to a decreased adherence.

  • Alarm
  • Inappropriate therapy
  • Obesity
  • Outcome
  • Wearable cardioverter-defibrillator
Citation (ISO format)
KOVACS, Boldizsar et al. High incidence of inappropriate alarms in patients with wearable cardioverter-defibrillators: findings from the swiss WCD registry. In: Journal of clinical medicine, 2021, vol. 10, n° 17, p. 3811. doi: 10.3390/jcm10173811
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ISSN of the journal2077-0383

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