1. Department of Cardiology, University Hospital Groningen, P.O. Box 30.001, 9700 RB Groningen, The Netherlands
2. Heart Failure Clinic, Franciscus Hospital Roosendaal, P.O. Box 999, 4700 AZ Roosendaal, The Netherlands
3. Department of Cardiology, Franciscus Hospital Roosendaal, P.O. Box 999, 4700 AZ Roosendaal, The Netherlands