7 lines (6 with data), 252 Bytes

m210a 0 128 0 14:35:00 19/06/1991
# Start time=14:35
# First beat=14:35:00.859
# <age-range>: 55-59, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.585,  <RR-high-limit(sec)>: 0.945
# Note: recording with a timing signal, flutter-compensated