7 lines (6 with data), 248 Bytes

m254a 0 128 0 16:05:00 26/02/1991
# Start time=16:05
# First beat=16:12:17.375
# <age-range>: 65-69, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.593,  <RR-high-limit(sec)>: 0.906
# Note: reel-to-reel recording, not flutter-compensated