[Idiopathic atrial fibrillation: clinical-instrumental characterization and thromboembolic risk]. FT Fibrillazione atriale idiopatica: caratterizzazione clinico-strumentale e rischio tromboembolico.

Ninety-two patients with diagnosis of lone atrial fibrillation (AF) were retrospectively identified by our in-hospital records. Among the 92 patients, 62 were males and 30 females. Mean age was 50 +/- 15 years (range 13-81). In 30% of the patients mild to moderate systemic hypertension was present. None had thyroid dysfunction. At the time of our first clinical observation, AF showed the following characteristics: recurrent AF in 58% of the cases (53 patients), chronic AF in 16% of the cases (15 patients) and first episode of AF in 26% of the cases (24 patients). Patient's symptoms were: palpitation in 73% of the cases, dyspnea in 24%, asthenia in 22%, chest pain in 19%, dizziness in 19% and syncope in 9% of the cases. In 9% of the subjects AF was asymptomatic. Recurrent AF presented with more than one episode per day in 12% of the cases, one per week in 16% of the cases, one-two episodes in 1 month in 8% of the cases and between two and six episodes in 1 year in 33% of the cases. Cross-sectional echocardiography, evidenced a higher prevalence of left atrial enlargement in patients with chronic AF (7/15 cases = 47%) either compared to subjects with recurrent AF (5/53 cases = 9%, p < 0.005) or compared to subjects with a first episode of AF (3/24 cases = 11%, p < 0.05). Echocardiographic signs of left ventricular dysfunction (left ventricular enlargement or hypokinesia) were found in 27% of the patients with chronic AF and in 8% of the other two groups (NS).(ABSTRACT TRUNCATED AT 250 WORDS)