Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 52 8 2014 08 15 641 643 EN Shokoufeh Hajsadeghi Department of Cardiology, Rasoul-Akram Hospital, Iran University of Medical Sciences, Tehran, Iran. Saeed Oraii Department of Cardiology, Tehran Arrhythmia Center, Tehran, Iran. Hassan Riahi Department of Cardiology, Rasoul-Akram Hospital, Iran University of Medical Sciences, Tehran, Iran. Sayeyed Hashem Sezavar Department of Cardiology, Rasoul-Akram Hospital, Iran University of Medical Sciences, Tehran, Iran. Amir Hossein Ghanooni Department of Cardiology, Rasoul-Akram Hospital, Iran University of Medical Sciences, Tehran, Iran. Scott Reza Jafarian Kerman Department of Cardiology, Student Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran. Roghayeh Ahmahi Department of Medicine, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran. 2015 10 11 Atrial dissociation is characterized by different types of P waves captured in an electrocardiogram, usually seen in critically ill or post-cardiac transplantation patients. Our case demonstrates a 55-year-old man, presenting with chest pain (unstable angina) in the emergency department with transient double-P waves; representing the phenomenon. Our case did not have any of the suggested causes or any known cardiac problems; therefore, with ruling out other differential diagnosis, researches must be done to find another explanation, if repeated. https://acta.tums.ac.ir/index.php/acta/article/view/4560 https://acta.tums.ac.ir/index.php/acta/article/download/4560/4349