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.