[Natural history of patients with isolated atrial fibrillation].

Sixty three patients (pts) (aged less than or equal to 50 years) with a history of "lone" atrial fibrillation (AF) and normal heart size at radiological examination were followed-up for a mean period of 95 months (range 1-360). The arrhythmia remained paroxysmal in 43 pts, became chronic in 13, while in 7 could not be reverted to sinus rhythm at the time of first observation. Clinical examination was normal in 58 pts; in 23 echocardiography disclosed mild abnormalities. In 2 pts auscultation revealed a mid-systolic apical click, i n one a mid-systolic murmur and in 2 click and murmur together. These findings were correlated to slightly pathological echocardiographic patterns. M-mode and B-mode echocardiography yielded normal results in 35 pts and showed minor pathological findings in 28 (16 with paroxysmal AF and 12 with chronic AF). Thyroid hormones, tested in 58 pts, were within normal limits in 53, showed decreased T4 in 2 and increased T3 in 3 (2 of whom in treatment with amiodarone). During the follow-up period, no patient had a deterioration of the clinical status from the cardiovascular point of view. However, one patient suffered an episode of cerebral embolism, with rapid resolution, and one a cerebral transient ischemic attack. In conclusion "lone" AF has a favourable prognosis and systemic anticoagulation is not indicated, particularly in the absence of left atrial dilatation.