Scar Tissue Ablation
Chronic inflammation and atrial re-modeling lead to areas of fibrosis
and scar tissue generation, which serve as substrates for AF. Targeting
these areas with either voltage mapping or guided by magnetic resonance
images (MRI) has been proposed as an adjunctive strategy. A
meta-analysis by Blandino et al. (48) showed that ablation of low
voltage areas (LVA) in addition to PVI had a significantly improved
freedom from AF at a median follow-up of 17 months.
In contrast, two recent RCTs failed to show any difference in outcomes
with MRI-guided fibrosis ablation (49,50)However, in patients with low
grade fibrosis (grade I or II) PVI + fibrosis ablation led to a
reduction in atrial arrhythmia recurrence (51). Another unique approach
called box isolation of fibrotic substrates (BIFA) was successfully
tested by Kottkamp et al. (52). Fibrotic areas were identified with
voltage mapping and targeted with box isolation and freedom from AF was
achieved in 72.2 % of those patients. (Figure 6)