7 lines (6 with data), 248 Bytes

m278a 0 128 0 11:15:00 17/10/1989
# Start time=11:15
# First beat=11:22:36.687
# <age-range>: 55-59, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.484,  <RR-high-limit(sec)>: 1.023
# Note: reel-to-reel recording, not flutter-compensated