Potential benefit of transesophageal defibrillation: an experimental evaluation

• Published in: The American journal of emergency medicine 2006-07, Vol.24 (4), p.418-422
• Main Authors: Mischke, Karl, Schimpf, Thomas, Knackstedt, Christian, Zarse, Markus, Eickholt, Christian, Plisiene, Jurgita, Frechen, Dirk, Gramley, Felix, Schauerte, Patrick
• Format: Article
• Language: English
• Subjects: Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Animal models; Animals; Biological and medical sciences; Blood pressure; Body Weight; Cardiac arrhythmia; Cardiology. Vascular system; Cardiovascular disease; Defibrillators; Disease Models, Animal; Electric Countershock - instrumentation; Electric Countershock - methods; Electrodes; Emergency and intensive cardiocirculatory care. Cardiogenic shock. Coronary intensive care; Emergency medical care; Endocardial and cardiac valvular diseases; Esophagus; Female; Heart; Heart attacks; Heart rate; Hogs; Intensive care medicine; Ischemia; Latex; Medical sciences; Public access; Swine; Ventricular Fibrillation - therapy
• ISSN: 0735-6757; 1532-8171
• DOI: 10.1016/j.ajem.2005.12.014

Because of the proximity of the esophagus to the heart, transesophageal defibrillation might increase defibrillation success. We assessed the defibrillation threshold (DFT) of transesophageal defibrillation compared with standard transthoracic defibrillation. Defibrillation success and DFTs were determined in 22 female pigs with high (68 ± 4 kg, n = 12) or low body weight (39 ± 1 kg, n = 10). After induction of ventricular fibrillation, biphasic shocks were delivered between two cutaneous patch electrodes (sternal and apical position) or between an esophageal and two cutaneous patch electrodes in a sternal and apical position. The esophageal electrode was integrated into a latex sheath covering a standard transesophageal echocardiography probe. In 5 of 12 pigs with high body weight, external defibrillation failed despite 3 consecutive 200-J shocks, whereas subsequent transesophageal defibrillation was successful with the first shock. In the remaining 7 pigs, a more than 50% reduction in DFT was obtained with transesophageal defibrillation compared with standard biphasic external defibrillation (67 ± 27 vs 164 ± 23 J, P < .001). Pigs with lower body weight were successfully defibrillated by both transthoracic and transesophageal shocks. The DFT in pigs with low body weight was significantly lower using transesophageal defibrillation compared with transthoracic shocks (65 ± 15 vs 99 ± 38 J, P < .05). In this animal model, nonresponders to standard external defibrillation could successfully be defibrillated via an esophageal-cutaneous electrode configuration. Overall, an almost 50% DFT reduction was achieved by transesophageal defibrillation. Transesophageal defibrillation may provide an additional tool for terminating VF, which is refractory to external defibrillation, eg, in patients with very high body weight.