7 lines (6 with data), 249 Bytes

m204a 0 128 0 11:30:00 26/12/1990
# Start time=11:30
# First beat=11:30:00.343
# <age-range>: 60-64, <sex>: Female, <medication>: None
# <RR-low-limit(sec)>: 0.453,  <RR-high-limit(sec)>: 0.89
# Note: reel-to-reel recording, not flutter-compensated