While testing to the new standard IEC 60601-2-25:2011 (diagnostic ECGs, a update of the combination of IEC 60601-2-25:1993/A1:1999 and IEC 60601-2-51:2003), I made a table showing the differences between the two standards that might be of interest to others:
http://www.medteq.info/med/ECG_Diagnostic_Update
http://www.medteq.info/med/ECG_Diagnostic_Update