1. Department of Cardiology, Yeditepe University Hospital, Istanbul, Turkey (T.A.).
2. Kansas City Heart Rhythm Institute and Research Foundation (R.G.).
3. Kocaeli Derince Training and Research Hospital, Turkey (S.B.).
4. Istanbul-Cerrahpasa University Hospital, Turkey (K.Y.).
5. Liverpool Heart and Chest Hospital, United Kingdom (D.G.).