7 lines (6 with data), 258 Bytes

m204b 0 128 0 15:02:00 19/02/1991
# Start time=15:02
# First beat=15:09:03.796
# <age-range>: 60-64, <sex>: Female, <medication>: Moricizine
# <RR-low-limit(sec)>: 0.5,  <RR-high-limit(sec)>: 1.054
# Note: recording with a timing signal, flutter-compensated