心房細動と塞栓症 : 何時, どのような治療を始めるか？

Atrial fibrillation（AF）is a common arrhythmia and the prevalence of this arrhythmia is increasing as aging. Secondary AF is defined as AF with organic heart disease and lone AF as AF without it. The AF is divided into paroxysmal, persistent and chronic by its onset and persistence. It is clinically important that any type AF causes thromboembolic stroke. The preventive Qumadin therapy should be applied to patients with AF. Transesophageal echocardiography has been utilized for the diagnosis of left atrial thrombus and for the prediction of stroke. CHADS２ score is a clinical prediction rule for estimating the risk of stroke in patients with non-rheumatic AF. Patients with CHADS２ score_１should be treated with Qumadin. Rhythm control and rate control are two different strategies for the treatment of AF. There is no evidence that indicate better choice between rhythm control and rate control. Recently, inhibitors of the renin-angiotensin system have a potential to prevent new onset of AF in patients who has risk factors.