Abstract 4090: Substrate Modification Using Electroanatomically-guided Linear Ablation During Sinus Rhythm To Treat Post-infarction Ventricular Tachycardia
Catheter ablation of ventricular tachycardia (VT) in the setting of ischemic cardiomyopathy can be performed to modify the underlying substrate. We evaluated the efficacy of a linear VT ablation procedure based on sinus rhythm (SR) substrate maps to treat ischemic VT in consecutive patients.
Methods: In 110 consecutive patients with ischemic VT (56% not tolerated) catheter ablation was attempted. During SR left ventricular scar mapping was performed identifying scar tissue (bipolar voltages 1.5mV). Regionalization of VT-exit regions was performed based on pace-mapping within the scar border zone. Ablation was directed towards the identified exit region performing linear ablation along the scar border. ICD-holter interrogation was performed during follow-up.
Results: A mean of 2.7±1.6 different VTs were inducible per patient (total 286). In 97% (107) of all patients (74% of all inducible VTs ablated: 213/286) the clinical VT was successfully ablated. In 68 patients (62%) no sustained monomorphic VT (complete success) was inducible at the end of the ablation procedure whereas in 39 patients (35%) VTs (partial success) were still inducible. Over a median follow-up of 12 months (6 –39) 88 (80%) patients were free from any ventricular arrhythmia. 19 successfully ablated patients had recurrences in between 6 to 36 months post intervention but the number of episodes treated by the ICD was significantly reduced (16±4 within 3 months (3±2) (p=0.02). No difference in patients with tolerated compared to non-tolerated VTs were detected (recurrences in 7/48 (15%) tolerated and 15/62 (24%) non-tolerated; p=0.13). There was a significant difference in freedom from any VT in patients with complete (88%) versus partial success (72%) (p=0.04).
Conclusions: Substrate modification targeting only the scar-border zone including the VT exit site based on SR-maps is highly effective in suppressing the occurrence of a clinical VT in patients with remote myocardial infarction (97%). Based on the electro-anatomical findings complete freedom from any ventricular arrhythmia over a median of 1 year can be achieved in 80% of all patients. No difference in regard to freedom from any ventricular arrhythmia can be documented in patients with tolerated and non-tolerated VTs.