Left atrial enlargement as a predictor of recurrences in lone paroxysmal atrial fibrillation

BACKGROUND: A mild increase in left atrial (LA) size predicts arrhythmia onset and adverse events in patients with lone paroxysmal atrial fibrillation (LPAF). However, the role of LA size as a predictor of LPAF recurrences is still controversial. OBJECTIVE: The potential role of LA size in affecting the frequency of recurrent episodes in patients with LPAF was investigated. METHODS: Fifty-one patients who were admitted for a first episode of LPAF and presenting with one recurrence (group A, n=20), two or three recurrences (group B, n=18), or four or more recurrences (group C, n=13) during an average follow-up period of two years were retrospectively selected. The M-mode LA anteroposterior diameter (LAAPd) was used as an echocardiographic surrogate of LA size. RESULTS: At baseline, LA size was normal or borderline in the control group, group A and group B, but significantly increased in group C. At two years' follow-up, a significant further LA enlargement from baseline was observed in group B (LAAPd 40+/-1.1 mm versus 40.7+/-1.2 mm, P<0.01) and in group C (LAAPd 41.4+/-1.6 mm versus 42.7+/-1.7 mm, P<0.001), while LA size remained substantially unchanged in the control group and in group A. CONCLUSIONS: Observations confirmed the association of increased LA size and LPAF onset, and provide the first evidence for a potential role of LA progressive enlargement as a predictor of arrhythmic recurrences.