We report a case of vagally mediated atrial fibrillation on a young otherwise healthy man, with straight type ST-segment elevation in inferolateral leads that resolved a few hours after restoration of sinus rythm, a phenomenon that has never been previously reported. Even though no definite conclusion about the underlying mechanism of the ST-elevation can be made, this effect might probably be the result of intense parasympathetic tone and could be used to differentiate the causality.