The Journal of Tehran University Heart Center aims to publish the highest quality material, both clinical and scientific, on all aspects of cardiovascular Medicine. It includes articles related to research findings. Technical evaluations, and reviews. In addition, it provides a forum for the exchange of information on all aspects of Cardiovascular Medicine, including educational issues. “ the journal of Tehran University Heart Center” is an International, English language, peer reviewed journal concerned with Cardiovascular Medicine. It is an official Journal of the Cardiovascular Research Center of the Tehran University of Medical Sciences (in collaboration with the Iranian Society of Cardiac Surgeons) and is published quarterly. Papers submitted to this journal which do not adhere to the Instructions for Authors will be returned for appropriate revision to be in line with the instructions for authors. They may then be resubmitted. Submission of an article implies that the work described has not been published previously (except in the form of an abstract or as part of a published lecture or academic thesis), that it is not under consideration for publication elsewhere, that its publication is approved by all authors and tacitly or explicitly by the responsible authorities where the work was carried out, and that, if accepted, it will not be published elsewhere in the same form. In English or in any other language, without the written consent of the publisher.