Abstract
BACKGROUND: In clinical trials, manufacturer-specific, strategic programming of implantable cardioverter-defibrillators (ICDs), including faster detection rates, reduces unnecessary therapy but permits therapy for ventricular tachycardia/ventricular fibrillation (VF). Present consensus recommends a generic rate threshold between 185 and 200 beats per minute, which exceeds the rate tested in clinical trials for some manufacturers. In a case series, we sought to determine the relationship between programmed parameters and failure of modern ICDs to treat VF.
METHODS AND RESULTS: We reviewed cases in which normally functioning ICDs failed to deliver timely therapy for VF from April 2015 to January 2017 at 4 institutions. Of 10 ambulatory patients, 5 died from untreated VF, 4 had cardiac arrests requiring external shocks, and 1 was rescued by a delayed ICD shock. VF did not satisfy programmed detection criteria in 9 patients (90%). Seven of these patients had slowest detection rates that were consistent with generic recommendations but not tested in a peer-reviewed trial for their manufacturer's ICDs. Manufacturer-specific factors interacted with fast detection rates to withhold therapy, including strict VF episode termination rules, enhancements to minimize T-wave oversensing, and features that restrict therapy to regular rhythms in ventricular tachycardia zones. Untreated VF despite recommended programming accounted for 56% of sudden deaths and 11% of all deaths during the study period.
CONCLUSIONS: Complex and unanticipated interactions between manufacturer-specific features and generic programming can prevent therapy for VF. More data are needed to assess the risks and benefits of translating evidence-based detection parameters from one manufacturer to another.
Original language | English |
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Article number | e005305 |
Journal | Circulation: Arrhythmia and Electrophysiology |
Volume | 10 |
Issue number | 9 |
Number of pages | 41 |
ISSN | 1941-3149 |
DOIs | |
Publication status | Published - 2017 |
Keywords
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- Defibrillators, Implantable
- Electric Countershock
- Humans
- Male
- Middle Aged
- Prosthesis Failure
- Risk Factors
- Ventricular Fibrillation
- Journal Article