1. 1 Echocardiography Department, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
2. 2 Electrophysiology Department, Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran
3. 3 Research Department, Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran
4. 4 Tehran Heart Center, Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran
5. 5 Bahar Hospital, Shahroud University of Medical Sciences, Shahroud, Iran
6. 6 Research Development Center, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran
7. 7 Student's Scientific Research Center, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran