Impact of defibrillator-can size on defibrillation success with a single-lead unipolar system

• Published in: The American heart journal Vol. 131; no. 2; pp. 261 - 265
• Main Authors: Newby, Keith H., Moredock, Lynn, Rembert, Judith, Marcus Wharton, J., Natale, Andrea
• Format: Journal Article
• Language: English
• Published: New York, NY Mosby, Inc 01.02.1996; Elsevier
• Subjects: Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Animals; Biological and medical sciences; Defibrillators, Implantable; Dogs; Electric Countershock - methods; Electric Impedance; Electrodes, Implanted; Emergency and intensive cardiocirculatory care. Cardiogenic shock. Coronary intensive care; Equipment Design; Intensive care medicine; Medical sciences; Fissipedia; Intensive cardiocirculatory care; Carnivora; Treatment efficiency; Instrumentation therapy; Vertebrata; Mammalia; Energy; Animal; Technique; Defibrillation; Dog; Unipolar derivation; Defibrillator
• ISSN: 0002-8703; 1097-6744
• DOI: 10.1016/S0002-8703(96)90351-8

In a study of 11 dogs, we assessed whether the defibrillation energy requirements of a single transvenous right ventricular electrode/defibrillator can system depended on the can size. We compared the defibrillation threshold obtained with 65% fixed-tilt biphasic shocks with 20, 40, and 80 ml surface area defibrillator cans. The energy was delivered between a right ventricular coil inserted through the jugular vein and the can placed in the subcutaneous tissue of the left superior chest wall. The testing order of each can size was randomly determined. Triplicate defibrillation thresholds were obtained with each can. Despite a higher impedance (20 ml 85 ± 22 ohms vs 80 ml 71 ± 16 ohms, p < 0.01), the 20 ml can resulted in a similar defibrillation threshold compared with the 80 ml (20 ml 7.6 ± 2.8 J vs 80 ml 7.5 ± 3.4 J) and the 40 ml cans (20 ml 7.6 ± 2.8 J vs 7.5 ± 3.4 J). In conclusion, with the unipolar lead system the can size does not appear to be a factor limiting defibrillation success. Even a can the size of a pacemaker does not appear to significantly affect the defibrillation efficacy of this lead system.