Background:

Ventricular tachycardia (VT) are common in structural heart diseases and ablation of arrhythmogenic substrate is well established and recommended to improve outcome. The currently available data on the use of different ablation strategies for different aetiologies of the underlying disease have so far failed to demonstrate an advantage for one of the selected strategies. In the present study we elucidate periprocedural characteristics and outcome of patients with ischemic (ICM) and dilative (DCM) cardiomyopathy underwent substrate-based ablation.

Methods and Results:

The NECKAR-VT included a total of 93 patients (ICM n=67 vs DCM n=26) with a follow up period of one year in a single center retrospective registry. Patients with ICM showed a better outcome in terms of reduction and freedom of VT episodes and occurrence of syncope than patients with known DCM. Furthermore, mortality of any cause after catheter-based ablation was significantly lower in patients with ICM than in subjects with DCM (ICM n=2 vs DCM n=4, p=0.02). In the presence of ICM, scarring could be detected especially in the apical-anterior parts of the left ventricle, whereas in DCM-patients diffuse fibrosis involving the subepicardial tissue was observed. These findings are associated with increased VT-recurrence rate. Regarding the ablation strategy it could be shown that late potential abbolishment in addition to ablation of the VT exit - in cases where a hemodynamic stable VT was inducible - patients developed significantly higher freedom from recurrence after the first year of follow-up.

Conclusion:
Patients with DCM showed significantly lower recurrence-free survival compared to patients with ischaemic cardiomyopathy, regardless of the ablation strategy performed. Substrate based ablation strategy is feasible for ICM and DCM patients, whereas additional ablation of the VT exit improve outcome. Further data are needed to determine the ideal ablation strategy based on the underlying aetiology.