title: Effects of radiofrequency catheter ablation on patients with permanent pacemakers.
abstract: The objective of this study was to assess the effects of radiofrequency energy application on implanted pacemaker functions. Radiofrequency (RF) catheter ablation may cause pacemaker dysfunction due to electromagnetic interferences. The effects of RF on pacemaker behavior were studied in a series of 38 pacemakers, implanted 18 +/- 26 months prior to a RF procedure using either a right ventricular approach (AV node ablation, n = 35) or a left ventricular approach (left concealed accessory pathway ablation, n = 1; VT ablation, n = 2). The 38 patients (mean age 65 +/- 9 years) included 20 men and 18 women. Before energy applications, the 23 different pacemaker models were programmed to the VVI mode at the lowest available rate. The continuous surface ECG was recorded throughout the procedure. Thorough testing of the devices was performed before and after each RF delivery. Unusual pacemaker responses occurred in 20 of the 38 cases studied (53%). The impact of RF delivery was unpredictable, and variable dysfunctions were observed at different times for a given patient or could vary for a given model. Unusual pacemaker responses included pacemaker inhibition (n = 8), untoggled backup mode (n = 3), electromagnetic interference noise mode (n = 3), temporary RF-induced pacemaker tachycardia (n = 2), erratic behavior (n = 1), oversensing of RF onset and offset (n = 8), and transient loss of ventricular capture, (n = 1). Postablation, most devices automatically toggled back to full functionality. The three devices in the untoggled backup mode had to be reprogrammed to obtain normal operations. At the end of the procedure, pacing thresholds remained unchanged in all but one patient, in whom the increase in ventricular threshold was due to a nicked lead. In conclusion, implanted pacemakers frequently exhibit transient, unpredictable responses to RF energy application. Although all pacemaker functions were restored postablation, some devices had to be reset manually. The anomalies observed during the RF application argue for the simultaneous use of an external pacemaker in pacing-dependent patients.
authors.affiliation: Service de Cardiologie, CHU de Nancy, France.
authors.forename: N
authors.initials: N
authors.lastname: Sadoul
authors.forename: I
authors.initials: I
authors.lastname: Blankoff
authors.forename: C
authors.initials: C
authors.lastname: de Chillou
authors.forename: D
authors.initials: D
authors.lastname: Beurrier
authors.forename: M
authors.initials: M
authors.lastname: Messier
authors.forename: O
authors.initials: O
authors.lastname: Bizeau
authors.forename: I
authors.initials: I
authors.lastname: Magnin
authors.forename: B
authors.initials: B
authors.lastname: Dodinot
authors.forename: E
authors.initials: E
authors.lastname: Aliot
mesh_terms: D000328:Adult; D000368:Aged; D016477:Artifacts; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects*; D017115:Catheter Ablation / Q000009:adverse effects*; D004562:Electrocardiography; D004868:Equipment Failure; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000209:etiology; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D011184:Postoperative Period; D013610:Tachycardia / Q000209:etiology; D013997:Time Factors