Cardiac electrophysiology and conduction pathway ablation.

Invasive cardiac electrophysiological (EP) testing and transcatheter ablation are new methods available for the diagnosis and treatment of complex dysrhythmias. The purpose of this review is to familiarize anaesthetists with these procedures. The information presented combines a literature review with the authors' experience. This article reviews normal cardiac conduction, tachycardia pathogenesis, principles of cardiac EP study and techniques of conduction pathway ablation. The anaesthetic considerations, including the choice of anaesthetic agent, monitoring problems, drug interactions, special methods of dysrhythmia termination in the EP lab, and complications specific to these procedures, are detailed. Balanced general anaesthesia or monitored anaesthesia care (MAC) sedation with benzodiazepines, propofol and narcotics are acceptable. Several conclusions can be drawn: transcatheter ablation is an effective treatment for many reentry tachycardias; anaesthetic assistance for this procedure will increasingly be needed; anaesthesia can easily be provided without influencing accurate EP testing; overdrive pacing is the method of choice for terminating tachydysrhythmias in the EP lab.