%0 Journal Article %T Fl¨²ter IC %A Franquelo Morales %A Pablo %A Canales Hortelano %A C¨¦sar %A Vi£¿as Gonz¨¢lez %A Javier %A Valero Serrano %A Beatriz %J Revista Cl¨ªnica de Medicina de Familia %D 2012 %I Scientific Electronic Library Online %R 10.4321/S1699-695X2012000100011 %X antiarrythmic drugs commonly form part of the treatment regimens of primary care patients, especially in those with diagnosis of atrial fibrillation and flutter, conditions which usually require medication indefinitely. the side effects from their use are multiple and varied, and although these are widely described in the literature, it is advisable to be familiar with adverse effects, due to the frequent use of antiarrythmics and their potential danger. for example, flecainide, a class ic antiarrhythmic agent commonly used in patients with atrial fibrillation, can have proarrhythmic effects. we report the case of a patient previously diagnosed with atrial fibrillation and treated with flecainide, who developed regular wide qrs tachycardia with 1:1 atrioventricular conduction, known as class ic atrial flutter, causing initial confusion in diagnosis. %K flecainide %K atrial fibrillation %K anti-arrhythmia agents %K atrial flutter. %U http://scielo.isciii.es/scielo.php?script=sci_abstract&pid=S1699-695X2012000100011&lng=en&nrm=iso&tlng=en