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A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation
Published on: February 28, 2012
Patients Experiencing Unsuccessful Defibrillation From Implantable Cardiac Devices Remain at Elevated Risk Despite
Nathaniel Christian-Miller1, Muazzum Shah1, Kelly Arps1
1Division of Cardiovascular Medicine, Department of Electrophysiology, University of Michigan, Ann Arbor, Michigan, USA.
Insights
Failed defibrillation therapy in patients with implantable cardiac defibrillators (ICDs) occurred in 2.8% of cases. Both operative and non-operative management strategies yielded similar long-term outcomes, though repeat failures remained high.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Devices
Background:
- Unsuccessful defibrillation therapy in patients with implantable cardiac defibrillators (ICDs) can stem from patient or device factors.
- Management strategies following failed defibrillation therapy require further elucidation.
Purpose of the Study:
- To investigate the management approaches and outcomes for patients experiencing unsuccessful defibrillation therapies with implantable cardiac devices.
- To compare operative versus non-operative management strategies in this patient cohort.
Main Methods:
- A single-center cohort study included patients with ICDs who experienced unsuccessful defibrillation therapies.
- Demographic and device characteristics were analyzed.
- Survival free from recurrent unsuccessful device therapy was assessed for patients managed operatively versus non-operatively.
Main Results:
- Out of 1449 patients with ICDs, 40 (2.8%) had unsuccessful defibrillation therapies.
- Management included device reprogramming, anti-arrhythmic drugs, conservative therapy, lead addition, or pulse generator change.
- After a mean follow-up of 2.4 years, 55% experienced recurrent VT, with 15% having repeat failed defibrillator therapy.
- No significant difference in recurrent failed shocks was observed between operative and non-operative management groups.
Conclusions:
- The incidence of failed defibrillation therapy in ICD patients was 2.8%.
- Both operative and non-operative management approaches resulted in comparable long-term outcomes.
- A significant proportion (15%) of patients experienced repeat failed defibrillation therapy, indicating a persistent challenge.
Background:
Unsuccessful defibrillation therapy in patients with implantable cardiac defibrillators (ICDs) and ventricular tachytherapies may occur due to patient and/or device-related factors; appropriate management strategies after failed defibrillation therapy have been incompletely described.
Objectives:
To report on the management and outcomes of patients with implantable cardiac devices and unsuccessful defibrillation therapies.
Methods:
A single-center cohort of patients with ICDs was examined, patients with unsuccessful ICD therapies were included. Demographic and device features, and survival free from recurrent unsuccessful device therapy was examined among patients undergoing operative vs. non-operative management.
Results:
Among 1449 patients with ICDs, 40 patients (2.8%) were identified with unsuccessful defibrillation therapies (mean age 59 ± 15 years, ejection fraction 29% ± 16%, ischemic cardiomyopathy n = 27, 67.5%, secondary prevention device placement n = 22, 55%, transvenous ICD n = 34, 85%, subcutaneous ICD n = 6, 15%). Nonoperative management strategies included device reprogramming (n = 8), addition of a class III anti-arrhythmic (n = 7), or conservative therapy (n = 5). Operative management included addition of a transvenous lead (n = 10), addition of subcutaneous array (n = 8), or change in pulse generator (n = 2). A single-coil device was present in 18/20(90%) patients undergoing operative management compared to 10/20 (50%) with non-operative management (p = 0.16). There were no demographic or device differences between the two groups. After 2.4 ± 2.1 years follow up, repeat VT occurred in 22 patients (55%) including 6 patients (15%) with a repeat failed defibrillator therapy. There was no differences in the risk of recurrent failed shocks among patients with operative vs non-operative management (log rank p = 0.14).
Conclusions:
Among a large cohort of patients with ICD, the incidence of failed defibrillator therapy was 2.8%. With appropriate patient selection, both operative and non-operative management led to similar long-term outcomes; however, the overall incidence of repeat failed defibrillation therapy remained high at 15%.
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