Internal cardioversion for treatment of postoperative atrial fibrillation

Atrial fibrillation (AF) is the most common dysrhythmia following open heart surgery with or without cardiopulmonary bypass. In previous studies, the AF incidence varied between 25.0% and 60.0% of all patients. The conventional treatment of postoperative AF periods consists of antiarrhythmic medication, most frequently calcium channel antagonists, beta-adrenergic blockers, or amiodarone. If the pharmacological treatment is ineffective or leads to further impairment of hemodynamics, external electrical cardioversion under general anesthesia and simultaneous transesophageal echocardiography is performed. Systemic heparinization is recommended to prevent neurological events related to AF. In 1995, a new method for internal electrical cardioversion using epicardial wire electrodes with low shock energies was developed in a canine model. Since June 1997, this device for internal cardioversion that consisted of two multifilament stainless steel wires has been available clinically (TADpole followed by Syncrus heart wires, Guidant Corporation C and VS, Cupertino, California, USA). The safety and efficacy of this innovative strategy for treatment of postoperative AF has been investigated in two pilot studies. These studies demonstrated a success rate of internal cardioversion up to 92.9% with optimized pre-shock treatment that leads to a significant shortening of AF periods, with the expectation of reduction in hospital length of stay.