holter monitoring revealed significant differences between the minimal heart rate during sleeping ( group i : 48 +/- 10 bpm , mean +/- sd group ii : 32 +/- 4 bpm , probability less than 0.001 ) as well as in the average sinus cycle length for 24 hours ( group i : 848 +/- 88 ms , group ii : 1254 +/- 136 ms , p less than 0.001 ) with a very characteristic histogram .
C1444754
length
C1521970
characteristic