7 lines (6 with data), 252 Bytes

m238a 0 128 0 16:33:00 04/09/1990
# Start time=16:33
# First beat=16:40:52.906
# <age-range>: 55-59, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.453,  <RR-high-limit(sec)>: 0.984
# Note: recording with a timing signal, flutter-compensated