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Defibrillation with low voltage using a left ventricular catheter and four cutaneous patch electrodes in dogs
P A Guse1, K M Kavanagh, C A Alferness
1Department of Medicine, Duke University Medical Center, Durham, NC 27710.
Pacing and Clinical Electrophysiology : PACE
|March 1, 1991
Summary
This study found that a left ventricular catheter with four patches significantly lowers defibrillation thresholds (DFTs) compared to a right ventricular catheter. This configuration is promising for evaluating non-thoracotomy lead systems in implantable defibrillators.
Area of Science:
- Biomedical Engineering
- Cardiovascular Research
- Medical Devices
Background:
- Implantable defibrillators require effective lead configurations for successful defibrillation.
- Non-thoracotomy lead systems offer potential advantages but need optimized electrode placement.
- Determining lower defibrillation thresholds (DFTs) is crucial for evaluating new lead designs.
Purpose of the Study:
- To establish lower limits of defibrillation thresholds (DFTs) for evaluating novel non-thoracotomy lead configurations.
- To assess a lead system using a left ventricular catheter and four cutaneous patches for uniform electric field generation.
- To compare the efficacy of different electrode combinations in achieving defibrillation.
Main Methods:
- Eight anesthetized dogs were used to test defibrillation lead configurations.
- Defibrillating catheters were placed in the right ventricle (R), outflow tract (O), and left ventricle (L).
- Four cutaneous patch electrodes (4P) were applied to the thorax; DFTs were measured using a modified Purdue technique with biphasic shocks.
Main Results:
- The left ventricular catheter with four patches (L(-)----4P+) demonstrated significantly lower DFTs (3.2 +/- 1.6 J) compared to the right ventricular catheter with four patches (R(-)----4P+) (8.0 +/- 4.2 J).
- This configuration also resulted in reduced current requirements.
- Using four patches lowered DFTs compared to a single patch, and the outflow tract catheter was effective only with the right ventricular catheter.
Conclusions:
- The left ventricular catheter and four patch configuration offers a lower defibrillation threshold, indicating improved efficiency.
- This configuration is a viable option for evaluating non-thoracotomy lead systems for implantable defibrillators.
- Optimizing electrode placement and configuration is key to improving defibrillation efficacy and reducing energy requirements.