The effect of different treatment strategies on left atrial size in patients with lone paroxysmal atrial fibrillation-a prospective cohort study.

Introduction: The effect of different treatment strategies of atrial fibrillation on left atrial (LA) size has not been compared in lone paroxysmal atrial fibrillation. The objective of the present study was to evaluate the evolution of LA size over time in patients who underwent different treatment interventions.

Methods And Results: Two hundred forty patients with lone paroxysmal atrial fibrillation were assigned to four groups. The circumferential pulmonary vein ablation (CPVA) group (n = 60) was treated with CPVA, segmental pulmonary vein isolation (SPVI) group (n = 60) with SPVI, AMIO group (n = 60) with amiodarone alone, and AMIO + LO group (n = 60) with amiodarone plus losartan. LA diameter was measured with transthoracic echocardiogram at baseline, 3, 6, 9, and 12 months after the interventions. In the CPVA group, LA size at third, sixth, ninth, and 12th month had a significant decrease than that at baseline and in the other three groups. LA size in patients with atrial fibrillation recurrence in the four groups was significant higher than that in patients with no atrial fibrillation recurrence (P = 0.002-0.001).

Conclusion: The results suggested that a shortened LA size is not consistent with improved sinus rhythm maintenance. Although maintenance of sinus rhythm is not the only factor in determining shrinking or enlargement of the left atrium, inhibiting or eliminating activity of the pulmonary vein is very important for paroxysmal atrial fibrillation. Atrial fibrillation recurrence is a main factor contributing to enlargement of the LA.