© 2003 by European Society of Cardiology
The effect of endocardial defibrillator shocks on basic atrial electrophysiology in man
Is post cardioversion atrial electrical remodelling artefact?
1Department of Cardiology, Eastbourne General Hospital East Sussex, U.K.; 2Department of Cardiology, Guys and St Thomas NHS Trust London, U.K.; 3Department of Cardiology, St Peters Hospital Chertsey, Surrey, U.K.
AIMS: To determine the effect of an endocardial DC shock on the basic electrophysiology of the human atrium if delivered in sinus rhythm.
METHODS AND RESULTS: A 5J endocardial R wave synchronized DC shock was delivered in 10 patients in stable sinus rhythm during ICD implantation for ventricular arrhythmias. There was no prior history of atrial fibrillation. Monophasic action potential duration (APD) and atrial effective refractory periods (AERP) were evaluated before, 1 min post DC shock, and 15 min post shock. These parameters were assessed at basic cycle lengths and at atrial paced cycle lengths of 600 ms and 400 ms at two right atrial sites; mid lateral right atrial wall (MRLA) and the right atrial appendage (RAA). There were no significant differences in APD 90, AERP or atrial refractory dispersion at any site or drive cycle length before, immediately after or 15 min after shock delivery.
CONCLUSIONS: There are no significant changes in basic electrophysiological parameters following a DC shock delivered in sinus rhythm in patients with no prior history of atrial fibrillation. This suggests that atrial electrical remodelling occurs as a result of atrial fibrillation and is unrelated to shock artefact.
Key Words: Atrial fibrillation, atrial electrical remodelling, DC cardioversion, monophasic action potentials, atrial effective refractory period
Correspondence: Dr Neil Sulke, Department of Cardiology, Eastbourne General Hospital, Kings Drive, Eastbourne, East Sussex, BN21 2UD, U.K. Tel.: +44 1323 435869; Fax: +44 1323 435821; E-mail: sulke{at}btinternet.com