1. From the Department of cardiology, Marien Hospital Witten, Witten, Germany
2. Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA
3. Department of Cardiology, Faculty of Medicine, Menoufia University, Menoufia, Egypt
4. Department of Medical Research, Faculty of Medicine, Fayoum University, Fayoum, Egypt
5. Department of Cardiology, Faculty of Medicine, Cairo University, Menoufia, Egypt
6. Internal Medicine Department, University of Toledo, Toledo, OH.