1. 1 Department of Echocardiography, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
2. 2 Department of Cardiology, North Khorasan University of Medical Sciences, Bojnurd, Iran
3. 3 Department of Electrophysiology, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
4. 4 Department of Cardiology, University Heart Center Zurich, Zurich, Switzerland