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Failed Maximal Defibrillation Threshold Testing in the Subcutaneous Implantable Cardioverter Defibrillator
Joshua D Levine1, Catherine Ellins, Nancy Winn
1University of Florida Health Science Center, Jacksonville, Fla., USA.
Insights
Subcutaneous implantable cardioverter-defibrillators (S-ICD) pose challenges in obese patients. This case highlights component migration and defibrillation threshold testing difficulties in a patient with a BMI of 44.
Area of Science:
- Cardiology
- Biomedical Engineering
- Medical Devices
Background:
- The Subcutaneous Implantable Cardioverter-Defibrillator (S-ICD) is an option for sudden cardiac death prevention.
- Limited data exists for S-ICD implantation in patients with obesity (BMI > 40).
Observation:
- A case of a 40-year-old male with a BMI of 44 and reduced ejection fraction (25%) undergoing S-ICD implantation.
- Initial defibrillation threshold (DFT) testing failed; component migration was observed on radiography despite fluoroscopic guidance.
Findings:
- Repositioning components led to inconsistent DFT testing results.
- Obesity presents unique challenges for S-ICD implantation and device efficacy.
Implications:
- This case underscores the need for careful patient selection and procedural technique in obese individuals receiving S-ICDs.
- Further research is needed to optimize S-ICD performance and implantation strategies in the obese population.
Abstract:
The subcutaneous implantable cardioverter defibrillator (S-ICD) registry included very few patients with a body mass index (BMI) greater than 40. We present a case of a 40-year-old male with a BMI of 44 and ejection fraction of 25% who underwent S-ICD implantation for primary prevention of sudden cardiac death in the setting of a nonischemic cardiomyopathy. Defibrillation threshold (DFT) testing failed at high output. A posterior to anterior radiograph demonstrated migration of the components despite positioning under fluoroscopy. After repositioning, repeat DFT testing showed an inconsistent efficacy. We discuss the probabilistic nature of DFT testing, clinical factors affecting the S-ICD implant in the obese population and offer a novel insight from this specific experience.
