1. Department of Medicine, Dow University of Health Sciences, Karachi, Pakistan
2. Department of Medicine, Ziauddin Medical University, Karachi, Pakistan
3. Department of Medicine, West Virginia University, Morgantown, WV, USA
4. Division of Cardiology, Department of Medicine, Henry Ford Hospital, Detroit, MI, USA
5. Department of Cardiovascular Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA