We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Inspiration Induced by Phrenic Nerve Stimulation Increases Internal Defibrillation Energy Requirements.
- Authors
Euler, David E.; Whitman, Teresa A.; Kallok, Michael J.
- Abstract
Introduction: The purpose of this study was to systematically evaluate the effects of active inspiration induced by phrenic nerve stimulation on the energy required for 50% successful defibrillation (E50). Methods and Results: Shocks (95-μF biphasic waveform) were delivered after 10 .seconds of ventricular fibrillation between a right ventricular coil and left pectoral test can in ten anesthetized pigs (25 to 37 kg). Using a 1-J step size, the E50 was determined with an up/down, three-reversal method. Positive-pressure ventilation was halted just before fibrillation, and shocks were delivered during expiration or at the end of 2 seconds of bilateral phrenic stimulation (50 Hz, 0.3 msec, 5 to 6 V). Phrenic stimulation produced inspiratory volumes that were 15.3 ± 1.7 mL/kg (mean ± SD). The E50 was 9.8 ± 1.9 J during expiration and increased to 13.0 ± 1.7 during inspiration (P = 0.001). The leading-edge voltage at the K50 was 451 ± 46 V during expiration and 519 ± 33 V during inspiration (P = 0.001). The leading-edge current at the E50 was 9.7 ± 1.0 A during expiration and increased to 11.3 ± 1.4 A during inspiration (P = 0.002). The average impedance was 47.8 ± 2.7 ft during expiration and 47.3 ± 3.3 11 during inspiration (P = 0.12). Conclusion: Inspiration induced by phrenic stimulation results in a 31% increase in the E50 compared with expiration. The decrease in shock efficacy occurs in the absence of a change in impedance. Active inspiration may alter the distribution of the electrical field leading to a decrease in shock efficacy.
- Subjects
NEURAL stimulation; VENTRICULAR fibrillation; CARDIAC arrest; PHRENIC nerve; ANIMAL models in research; ELECTRIC countershock
- Publication
Journal of Cardiovascular Electrophysiology, 1999, Vol 10, Issue 10, p1402
- ISSN
1045-3873
- Publication type
Article
- DOI
10.1111/j.1540-8167.1999.tb00196.x