7 lines (6 with data), 248 Bytes

m271a 0 128 0 14:20:00 19/03/1990
# Start time=14:20
# First beat=14:39:45.070
# <age-range>: 70-74, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.671,  <RR-high-limit(sec)>: 1.281
# Note: reel-to-reel recording, not flutter-compensated