1 1st Department of Internal Medicine, St. Anna Hospital, Masaryk University, Brno, Czech Republic; Centre of Biostatistics and Analyses, Masaryk University, Brno, Czech Republic.
The publisher regrets that this was an accidental duplication of an article that has already been published in Eur. J. Echocardiogr., 4 (2003) 262-271, . The duplicate article has therefore been withdrawn.