1. King Fahad Cardiac Center, King Khalid University Hospital; College of Medicine, King Saud University; PO Box 7805, Riyadh 11472 Kingdom of Saudi Arabia
2. Prince Salman Heart Center; King Fahd Medical City; Riyadh Kingdom of Saudi Arabia
3. Department of Medicine; University of Manitoba; Winnipeg Canada
4. Security Forces Hospital; Riyadh Kingdom of Saudi Arabia
5. North West Armed Forces Hospital; Tabuk Kingdom of Saudi Arabia
6. King Abdulaziz University Hospital; Jeddah Kingdom of Saudi Arabia