Surgical VT Ablation
When VT ablation was failed despite endo/epi ablation, eligible patients
would be rescheduled for surgical VT ablation. A quadripolar catheter
was advanced into right ventricle for mapping reference and VT
induction. Left limited thoracotomy would be the preferred access for
surgical VT ablation. If the patient required other concomitant cardiac
surgery, a median sternotomy would be performed instead.
Three-dimensional electroanatomic mapping system (EnSite NavX, St. Jude
Inc., St. Paul, MN, USA) was used to guide the procedure. The mapping
strategy was similar to that of endocardial and epicardial approach. An
irrigated ablation catheter (CoolFlex, St. Jude, Inc., St. Paul, MN,
USA) with a flow rate of 30-60mL/min was used. Since the impedance
recorded by the catheter tip was often higher than 200Ω due to its
exposure to air, the upper limit of impedance should be reset to the
maximum allowed by the RF generator. The tip of ablation catheter was
manually pressed against the epicardial surface to maximize the contact
force.