Right atrial reverse remodeling after pulmonary vein isolation: Analyzing changes in volume and function using...

Successful pulmonary vein isolation (PVI) promotes left atrial (LA) reverse remodeling, but its effect on right atrial (RA) remodeling remains unclear.

The purpose of this study was to assess the impact of radiofrequency (RF) PVI on RA volumes and function in patients with atrial fibrillation by using cardiac magnetic resonance imaging.

Forty-three patients with atrial fibrillation (32 (74.4%) males; mean age 61±7 years) undergoing first RF PVI, without atrial flutter ablation, underwent 3 cardiac magnetic resonance scans: pre-PVI, early (<72 hours) post-PVI, and 3 months post-PVI. Indexed atrial volumes (RA maximal/minimal volume index and LA maximal/minimal volume index) and function were derived from 2- and 4-chamber cine images, with longitudinal atrial strain analyzed using feature tracking.

Early post-PVI, RA minimal volume index significantly decreased (from 28.7±10.3 to 26.0±9.9 mL/m²; P=.03) while RA emptying fraction significantly increased (from 37.3%±11.5% to 41.7%±10.1%; P=.03). At 3 months, both RA minimal volume index and RA maximal volume index showed further significant reductions compared with baseline (from 28.7±10.3 to 24.8±8.8 mL/m²; P=.002 and from 45.2±11.8 to 40.3±11.9 mL/m²; P<.001, respectively). During this period, RA functional improvement persisted, as evidenced by RA reservoir and contractile strain (from 16.2%±4.1% to 18.9%±3.6%; P=.003 and from 6.6%±2.6% to 8.3%±2.8%; P=.005, respectively). LA volumes remained unchanged early post-PVI, but at 3 months, LA maximal volume index significantly decreased compared with baseline (from 46.1±13.0 to 39.1±11.3 mL/m²; P<.001). LA function, demonstrated by reservoir and contractile strain, was significantly diminished early post-PVI, which persisted at 3 months compared with baseline (from 18.6%±4.0% to 17.0%±3.4%; P=.04 and from 8.5%±3.0% to 6.9%±2.4%; P<.01, respectively).

This study demonstrates that RF PVI results in reverse biatrial remodeling, with significant reductions observed in RA and LA volumes. RA function showed a significant improvement post-PVI, while LA function demonstrated persistent impairment at 3 months, possibly because of LA ablation scarring.