13th International Congress
THE "NEW FRONTIERS"
OF ARRHYTHMIAS 1998

January 24-31, 1998
Marilleva, Trento, Italy

RT-184

Transvenous internal cardioversion of atrial fibrillation using single and dual pathways simultaneous biphasic shocks and leads currently used for ventricular defibrillation

Roberto Neri, Piero Palermo, Antonio Silvio Cesario, Daniela Baragli, Elisabetta Amici, Maria Teresa Laudadio*, Angelo De Rosa*, Francesco DeSeta*, Giancarlo Gambelli.
Division of Cardiology, GB Grassi Hospital, Rome, *Medtronic Italia, Italy

Introduction

Atrial fibrillation is the most common arrhythmia resulting in hospital admission, is one of the main factor in the genesis of embolic strokes, may contribute to the development of congestive heart failure and is associated with an increased of risk of death¹. The efficacy of antiarrhythmic drug is limited and the potential for proarrhythmia and negative inotropic effects may outweigh the potential benefit of restoring sinus rhythm². Transthoracic electrical cardioversion effectively restores sinus rhythm but requires general anesthesia. Low energy internal cardioversion has been recently introduced for interruption of atrial fibrillation without general anesthesia³ and an implanted atrial defibrillator has been proposed for the treatment of patients with paroxysmal atrial fibrillation that is medically refractory⁴. It has to be recognized, however, that ventricular fibrillation induction might result from a poorly synchronized low energy atrial shock⁵ and that the risk of ventricular proarrhythmia could be significant, even after an optimally synchronized atrial shock, in patients already having ventricular arrhythmic substrates. Moreover, atrial fibrillation often complicates the use of implantable cardioverter defibrillator for ventricular tachy-arrhythmias⁶ and, therefore, it seems desirable to develop a device with the capability for low energy atrial defibrillation implemented into current ICD systems allowing availability of both atrial and ventricular defibrillation. This study was undertaken to evaluate efficacy, safety and tolerability of transvenous internal cardioversion of atrial fibrillation using single and dual pathways biphasic shocks and leads currently used for ventricular defibrillation.