Reduction in left atrial and pulmonary vein dimensions after ablation therapy is mediated by scar

Figures

• 

  Fig. 1. CMR images in AF patients. Four-chamber slice with RSPV and LSPV at the moment of maximum LA dilatation in patients before (A) and after (B) PVI ablation. Dotted lines: PV diameters. Closed circles: LA septal wall. Open circles: RSPV anterior wall. Closed triangle: RSPV posterior wall. Open triangle: LSPV posterior wall. Four-chamber slice with RIPV before (C) and after (D) ablation. Dotted lines: RA and LA surface areas for volume estimation. Asterisks: RIPV anterior wall. Hashtag: RIPV posterior wall. Two-chamber slice before (E) and after (F) ablation. Open square: LA posterior wall. Closed square: LA inferior wall. LGE CMR before ablation (G) and after ablation (H). The scar formation in the PV walls after ablation is noted.

• 

  Fig. 2. Ablation-induced changes in PV diameter and scar. A: The PV diameter decreased after PVI. A mean of ablation-induced PV diameter change was calculated in each patient and hypothesis-tested against a theoretical mean of 0 (one sample Student’s t-test). B: The diameter of the ablated RPV decreased after ablation in sheep, while the diameter of the control LPV (intra-sheep mean) was unchanged. C: There existed a negative linear correlation between PV diameter change and extent of PV scar (logarithmically transformed). D: Collagenous ablation scar occurred in the RPV (left panel), but not in the LPV of sheep (right panel).

• 

  Fig. 3. Regional wall contractility before and after ablation in patients. The longitudinal strain curves before (A) and after (B) ablation of the posterior RSPV wall where x = 0 is the moment immediately after atrial contraction. We considered the last 20% of the curve as the atrial contractile phase (blue shade). Localized contractility was quantified as the magnitude of the strain during this phase. C: The PV contractility index decreased after ablation whereas the LA contractility index remained unchanged.

• 

  Supplementary Fig. 1. Cardiac magnetic resonance images in healthy sheep. Trans-axial slice with RPV at the moment of maximum LA dilatation in sheep before (A) and after (B) localized RPV ablation. Slice with LIPV and LSPV before (C) and after (D) ablation. Dotted lines: PV diameters.