Scaling current and energy with body weight: requirements for the transthoracic ventricular defibrillation of calves as they grow from 50 to 150 kg.
- 1 July 1979
- journal article
- research article
- Published by Wolters Kluwer Health in Circulation
- Vol. 60 (1) , 187-195
- https://doi.org/10.1161/01.cir.60.1.187
Abstract
To test the hypothesis that the effectiveness of a shock in achieving ventricular defibrillation is relatively independent of body weight if electrode diameter is proportional to the one-third power and current is proportional to the two-thirds power of weight, we studied defibrillation rates in 10 calves as they increased weight. At 50 kg, each calf was subjected to 20 fibrillation-defibrillation episodes using 10.3-cm diameter electrodes and 32-amp, 4-msec rectangular pulses for defibrillation. Two days after the original study, each calf underwent 20 additional episodes involving 44-amp pulses. With the specified scaling of electrode diameter and pulse amplitude, the two studies were repeated at weight intervals of 25 kg as the animals grew. Six calves survived. In the study that started with 32-amp pulses, first-shock success values of 28%, 49%, 66%, 51% and 23% were found in the six surviving calves at 50, 75, 100, 125 and 150 kg, respectively. The corresponding values were 93%, 96%, 93%, 94% and 91% in the study that started with 44-amp pulses. While the results of the 32-amp study fail to support our initial hypothesis, those obtained in the 44-amp current study appear compatible with the hypothesis.This publication has 9 references indexed in Scilit:
- Energy requirement for defibrillation of a markedly overweight patient.Circulation, 1978
- Transthoracic ventricular defibrillation in the 100 kg calf with unidirectional rectangular pulses.Circulation, 1977
- Low-Energy Ventricular Defibrillation and Miniature DefibrillatorsPublished by American Medical Association (AMA) ,1976
- Electrical requirements for ventricular defibrillation.BMJ, 1975
- Energy Dosage for Human Trans-Chest Electrical Ventricular DefibrillationNew England Journal of Medicine, 1974
- Electrical Dose for Ventricular Defibrillation of Large and Small Animals Using Precordial ElectrodesJournal of Clinical Investigation, 1974
- Transthoracic ventricular defibrillation with very high amplitude rectangular pulsesJournal of Applied Physiology, 1967
- Transthoracic Ventricular Defibrillation with Triangular and Trapezoidal WaveformsCirculation Research, 1966
- Transthoracic Ventricular Defibrillation with Square-wave Stimuli: One-Half Cycle, One Cycle, and Multicycle WaveformsCirculation Research, 1964