Related Experiment Video
Updated: Feb 26, 2026
A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation
Published on: February 28, 2012
Incidence and Determinants of Implantable Cardioverter-Defibrillator Therapy With Loss of and Impaired Consciousness
Alwin B P Noordman1, Michiel Rienstra1, Yuri Blaauw1
1Department of Cardiology, Heart Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
Insights
Many patients receive appropriate implantable cardioverter-defibrillator (ICD) therapy without loss of consciousness, potentially leading to unnecessary treatment. This can cause significant psychological distress, highlighting a need for better symptom assessment in ICD patients.
Area of Science:
- Cardiology
- Medical Devices
- Electrophysiology
Background:
- Implantable cardioverter-defibrillators (ICDs) are crucial for preventing sudden cardiac death.
- Some appropriate ICD therapies may be unnecessary, delivered without symptoms like loss of consciousness.
- Understanding patient-reported symptoms is key to evaluating ICD therapy appropriateness.
Purpose of the Study:
- To determine the incidence of appropriate ICD therapy with loss of consciousness.
- To assess the psychological impact of ICD therapy based on patient-reported symptoms.
- To identify factors associated with appropriate ICD therapy and consciousness impairment.
Main Methods:
- Prospective, single-center study of 100 consecutive ICD patients.
- Patients received ICD shock and/or ATP within 6 months prior.
- Questionnaires assessed patient-reported symptoms, focusing on loss of consciousness.
Main Results:
- 92% of patients experienced appropriate ICD therapy.
- Loss of consciousness occurred in 40% of patients with appropriate therapy (65% with shocks).
- Patients without loss of consciousness reported greater anxiety post-shock (60.0% vs 42.9%).
Conclusions:
- A significant number of patients receive appropriate ICD therapy without loss of consciousness.
- This suggests potentially unnecessary therapy and associated psychological impact.
- Further research is needed to refine ICD therapy delivery based on symptom presentation.
Introduction:
Implantable cardioverter-defibrillators (ICDs) are important in the prevention of sudden cardiac death. However, some appropriate ICD therapies may be considered unnecessary, delivered when patients do not experience symptoms of hemodynamic instability such as loss of consciousness. Therefore, we aimed to determine the incidence of appropriate ICD therapy with loss of consciousness and impaired consciousness, as well as the psychological impact following any ICD therapy, in patients with an ICD by investigating patient-reported symptoms.
Methods:
In this prospective, single-center study conducted at the University Medical Center Groningen (UMCG), 100 consecutive patients with an ICD for primary or secondary prevention indications who received ICD shock and/or ATP within the previous 6 months completed a questionnaire. The primary outcome was appropriate ICD therapy with loss of consciousness.
Results:
The patient population consisted of 100 patients, 92 (92.0%) of whom had appropriate therapy. The mean age was 62.7 ± 12.8 years and 21 (21.0%) were female. Loss of consciousness occurred in 40% of patients with appropriate ICD therapy and in 65% of patients with appropriate shocks. Determinants of appropriate ICD therapy with loss of consciousness included the shortest cycle length, ventricular fibrillation, the occurrence of shock, a secondary prevention indication for ICD, the presence of a CRT-D and the fragmentation and width of the QRS complex. The psychological impact of ICD shocks was considerable, with patients without loss of consciousness during ICD shocks suffering significantly more from anxiety than those with loss of consciousness (9 (60.0%) versus 12 (42.9%), p = 0.041).
Conclusions:
A considerable number of patients do not experience appropriate ICD therapy with loss of consciousness and thus experience potentially unnecessary therapy while still being at risk of sustaining the consequent psychological impact associated with ICD shocks.
Related Concept Videos
01:29Cardiomyopathy V: Interprofessional Care
01:29Disturbances in Heart Rhythm
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...
01:30Coronary Artery Disease III: Clinical Manifestations
01:30Cardiomyopathy II: Dilated Cardiomyopathy
01:19Acute Coronary Syndrome II: Pathophysiology and Clinical Manifestations
01:30Acute Coronary Syndrome I: Introduction