1. First Department of Cardiology, Interventional Electrocardiology and Hypertension; Jagiellonian University Medical College; Cracow Poland
2. Department of Cardiology; H. Klimontowicz Specialistic Hospital; Gorlice Poland
3. Department of Cardiology; Institute of Pediatrics; Jagiellonian University Medical College; Cracow Poland
4. Division of Cardiology; Kingston General Hospital; Queen's University; Kingston ON Canada