7 lines (6 with data), 252 Bytes

m169a 0 128 0 12:12:00 23/03/1990
# Start time=12:12
# First beat=12:23:55.398
# <age-range>: 45-49, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.445,  <RR-high-limit(sec)>: 1.312
# Note: recording with a timing signal, flutter-compensated