. 2011 May 31;41(5):235–240. doi: 10.4070/kcj.2011.41.5.235
Copyright © 2011 The Korean Society of Cardiology
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.