TY - CHAP M1 - Book, Section TI - Defibrillators A1 - Freeman, Brian S. A2 - Freeman, Brian S. A2 - Berger, Jeffrey S. PY - 2014 T2 - Anesthesiology Core Review: Part One Basic Exam AB - During defibrillation, a randomly timed high-voltage electric current is discharged across two electrodes placed on the chest of a patient in cardiac arrest. The purpose of defibrillation is to simultaneously depolarize a large critical mass of myocardium. As a result, nearly all ventricular myocytes will enter their absolute refractory periods, when no action potentials can be generated. Successful defibrillation means that the reentry focus underlying the ventricular dysrhythmia is now either quiescent or eliminated. At this point, the pacemaker with the highest automaticity (such as the sinus or atrioventricular nodes) will take over control of ventricular pacing and contraction with a proper sequence of depolarization and repolarization. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/29 UR - accessanesthesiology.mhmedical.com/content.aspx?aid=1102566582 ER -