Description:
<jats:title>Abstract</jats:title><jats:sec><jats:title>Background/Aim</jats:title><jats:p>We studied all patients admitted to hospital with first onset atrial fibrillation (<jats:styled-content style="fixed-case">AF</jats:styled-content>) to determine the probability of spontaneous conversion to sinus rhythm and to identify factors predictive of such a conversion.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>We retrospectively reviewed charts of 438 consecutive patients admitted to hospital with first onset <jats:styled-content style="fixed-case">AF</jats:styled-content> from 1 <jats:styled-content style="fixed-case">J</jats:styled-content>anuary 2006 to 31 <jats:styled-content style="fixed-case">D</jats:styled-content>ecember 2009. The patients were divided into two groups, recent onset <jats:styled-content style="fixed-case">AF</jats:styled-content> defined as <jats:styled-content style="fixed-case">AF</jats:styled-content> < 48 h or longer lasting <jats:styled-content style="fixed-case">AF</jats:styled-content>, defined as <jats:styled-content style="fixed-case">AF</jats:styled-content> > 48 h.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Spontaneous conversion occurred in 54% (<jats:italic>n</jats:italic> = 203; 95% confidence interval: 49–59%). In the group with first onset <jats:styled-content style="fixed-case">AF</jats:styled-content> < 48 h, spontaneous conversion occurred in 77%, compared with 36% in the group with first onset <jats:styled-content style="fixed-case">AF</jats:styled-content> > 48 h. Logistic regression analysis identified duration of <jats:styled-content style="fixed-case">AF</jats:styled-content> as a highly significant predictor of spontaneous conversion to sinus rhythm (odds ratio 5.9; 95% confidence interval: 4.0–8.6, <jats:italic>P</jats:italic> < 0.001).</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>Spontaneous conversion occurred in 54%, increasing to 77% when <jats:styled-content style="fixed-case">AF</jats:styled-content> had persisted less than 48 h.</jats:p></jats:sec>