7 lines (6 with data), 248 Bytes

m128a 0 128 0 11:09:00 13/06/1988
# Start time=11:09
# First beat=11:16:40.765
# <age-range>: 45-49, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.632,  <RR-high-limit(sec)>: 1.054
# Note: reel-to-reel recording, not flutter-compensated