Introduction: The incidence and significance of catheter-induced trauma to ventricular arrhythmias (VA) originating from the outflow tract (OT) area during radiofrequency ablation (RFA) have not been described yet.
Methods: Consecutive pts (n=340; 48% females, aged 57±11.6 years) undergoing RFA of right/left OT-VA (total 364 RFA procedures; 290 RVOT-VA and 74 LVOT-VA), were closely monitored for appearance of mechanical block of VA during catheter manipulation.
Results: Mechanical trauma to OT-VA was observed in 9 (2.4%) pts (55% females, aged 53.2±12 years): in 8 pts during RVOT ablation (2.8% procedures) and in 1 pt during LVOT ablation (1.3% procedures) (p=NS). Catheter-induced trauma was due to the ablation catheter in all pts. In 3 pts who underwent > 1 procedure, catheter-mechanical trauma occurred in only 1 procedure. In 3 pts (group I), the arrhythmia recurred spontaneously within a few minutes and was subsequently successfully ablated. In the remaining 6 pts (group II), RF was delivered at the site of the presumed catheter-induced trauma. In all 9 pts, the RFA procedure was acutely successful. However, the arrhythmia recurred during follow-up in 3 of 6 group II pts while no recurrence was recorded in all 3 group I pts.
Conclusion: Catheter-induced mechanical trauma occurs in a small percentage of pts with OT-VA during RFA. Its occurrence may influence the results of the course of the ablation procedure. RFA of OT-VA guided by catheter-induced trauma may correlate with a high rate of long-term VA recurrence.
