Combined Standby Transvenous Defibrillator and Demand Pacemaker.
Abstract
The major objective of this effort was to find the minimum energy required for reliable defibrillation. In working toward this objective six catheter types were designed and evaluated; the effects of two closely spaced (in time) defibrillation pulses applied to one and two adjacent sites within the ventricle was experimentally examined; the effects of polarity of both unipolar and bipolar defibrillation pulses were evaluated; a comparison of the energy requirements for intracardiac and epicardial defibrillation was performed; and the pacing thresholds of the relatively large area defibrillation catheters was determined. The lowest defibrillation energies observed (1.3 Joules) were obtained with a single pulse applied to the epicardial surface. There was no difference in the energy required for defibrillation due to pulse polarity. However, bipolar defibrillation requires about 50% less energy than unipolar defibrillation. Double pulses required more energy than single pulses in all cases evaluated. Defibrillation threshold energies are relatively independent of electrode area as long as the area is greater than a critical minimum. Pacing thresholds are one to two orders of magnitude greater with large area defibrillation electrodes than with conventional pacing electrodes. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1975
- Accession Number
- ADA097441
Entities
People
- Leo Rubin