Necessity of epicardial ablation for ventricular tachycardia after sequential endocardial approach

BACKGROUND: Catheter ablation (CA) of ventricular tachycardia (VT) is an important treatment option in patients with structural heart disease (SHD) and implantable cardioverter defibrillator (ICD). A subset of patients requires epicardial CA for VT.

OBJECTIVE: The purpose of the study was to assess the significance of epicardial CA in these patients after a systematic sequential endocardial approach.

METHODS: Between January 2009 and October 2012 CA for VT was analyzed. A sequential CA approach guided by earliest ventricular activation, pacemap, entrainment and stimulus to QRS-interval analysis was used. Acute CA success was assessed by programmed ventricular stimulation. ICD interrogation and 24h-Holter ECG were used to evaluate long-term success.

RESULTS: One hundred sixty VT ablation procedures in 126 consecutive patients (114 men; age 65±12years) were performed. Endocardial CA succeeded in 250 (94%) out of 265 treated VT. For 15 (6%) VT an additional epicardial CA was performed and succeeded in 9 of these 15 VT. Long-term FU (25±18.2month) showed freedom of VT in 104 pts (82%) after 1.2±0.5 procedures, 11 (9%) suffered from repeated ICD shocks and 11 (9%) died due to worsening of heart failure.

CONCLUSIONS: Despite a heterogenic substrate for VT in SHD, endocardial CA alone results in high acute success rates. In this study additional epicardial CA following a sequential endocardial mapping and CA approach was performed in 6% of VT. Thus, due to possible complications epicardial CA should only be considered if endocardial CA fails.