Publications by authors named "Jefferson Burroughs"

2 Publications

  • Page 1 of 1

"Tuned" defibrillation waveforms outperform 50/50% tilt defibrillation waveforms: a randomized multi-center study.

Pacing Clin Electrophysiol 2007 Jan;30 Suppl 1:S139-42

Rochester General Hospital, Rochester, New York, USA.

Introduction: A superior performance of a tuned waveform based on duration using an assumed cardiac membrane time constant of 3.5 ms and of a 50/50% tilt waveform over a standard 65/65% tilt waveform has been documented before. However, there has been no direct comparison of the tuned versus the 50/50% tilt waveforms.

Methods: In 34 patients, defibrillation thresholds (DFTs) for tuned versus 50/50% tilt waveforms in a random order were measured by using the optimized binary search method. High voltage lead impedance was measured and used to select the pulse widths for tuned and 50/50% tilt defibrillation waveforms.

Results: Delivered energy (7.3 +/- 4.6 J vs 8.7 +/- 5.3 J, P = 0.01), stored energy (8.2 +/- 5.1 J vs 9.7 +/- 5.6 J, P = 0.01), and delivered voltage (405.9 +/- 121.7 V vs 445.0 +/- 122.6 V, P = 0.008) were significantly lower for the tuned than for the 50/50% tilt waveform. In four patients with DFT >/= 15 J, the tuned waveform lowered the mean energy DFT by 2.8 J and mean voltage DFT by 45 V. For all patients, the mean peak delivered energy DFT was reduced from 29 J to 22 J (24% decrease). Multiple regression analysis showed that a left ventricular ejection fraction < 20% is a significant predictor of this advantage.

Conclusion: Energy and voltage DFTs are lowered with an implantable cardioverter defibrillator that uses a tuned waveform compared to a standard 50% tilt biphasic waveform.
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January 2007

Development of the implanted devices adjustment scale.

Dimens Crit Care Nurs 2005 Sep-Oct;24(5):242-8

University of Cincinnati-College of Nursing, Cincinnati, OH 45221-0038, USA.

Advances in microelectronics have resulted in exponential growth in the number of implanted medical devices. Most people do well adjusting to their devices, but others show signs of depression and/or anxiety. The Implanted Device Adjustment Scale (IDAS) was developed to measure how well a person is adjusting to an implanted device. First, a pool of items was generated and reviewed by 2 panels of clinicians and psychometricians for content validity. The revised version was then administered to a small sample that provided information about problematic items. Finally, a convenience sample of 45 persons (66% males) with implanted devices (18 pacemakers only, 37 cardioverter/defibrillators) completed the revised IDAS twice. After deleting weak items, the Cronbach alpha was 0.90. No age, gender, or device differences were found. Test-retest reliability was 0.92. The IDAS may be useful to evaluate how well a person is adjusting to her/his device. This may lead to more timely and appropriate interventions to improve outcomes.
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December 2005