Both ischemic (ICM) as non – ischemic cardiomyopathy (NICM) are associated with an increased risk of ventricular tachycardia (VT). Although ICD therapy might prevent sudden death from VT, patients with ICM or NICM may suffer from recurrent ICD therapies and antiarrhythmic drug side effects. In this study, we describe our experience with ablation of VT in patients with ICM or dilated cardimyopathy (DCM) being the most prevalent NICM.

Methods and results

185 patients suffering from aforementioned cardiomyopathies presented to our EP lab for VT (ICM 124/185 (67%) and NICM 61/185 (33%), male 168/185 (91%), age 61±14 years, left ventricular systolic function 31%±10 % (ICM) and 31%±11% (NICM), 177/185 (96%) of antiarrhythmic drugs.

Catheter ablation was performed due to sustained VT mostly originating from the left ventricle. The chosen mapping and ablation strategy was substrate based in 109/185 patients (59%), activation mapping in 20/185 patients (11%), pace map guided ablation in 19/185 patients (10%) or a combined approach in 37/185 patients (20%). The median procedure time in ICM was 178 minutes and in NICM 193 minutes. The median fluoroscopy time in ICM was 11 minutes and in NICM 10 minutes. Radiofrequency energy was applied in ICM for 38 minutes with a median power of 41 watts and in NICM for 28 minutes with a median power of 41 watts. There were complications in 19/185 (10%) patients (mostly groin complications), but no deaths.

After one ablation, during a median follow up time in ICM of 13±14 months and in NICM of 8±15 months, arrhythmia free survival in ICM was 52%  and in NICM 32% . Arrhythmia free survival was statistically significant different in patients with ICM compared to those with DCM presenting with VT (p=0.01).

Conclusions

In our patient population 52% of ICM and 32% of NICM patients showed freedom from recurrence of VT after one procedure, without an increased risk of periprocedural complications. In patients with ICM and DCM substrates are different in scar location, extent and transmurality. These differences seem to influence the accessibility of substrate, putative ablation targets and therefore the anticipated outcomes in patients presenting for catheter ablation with VT.