Epicardial Ablation Procedure
When endocardial VT ablation was unsuccessful, epicardial approach would
be attempted using subxiphoid access. Mapping and ablation strategies
were similar to the endocardial approach as described above. Coronary
angiogram was performed in all the patients before ablation to avoid
inadvertent damage of coronary artery. High output pacing was performed
in the area close to the course of phrenic nerve before ablation to
avoid phrenic nerve injury.