7 lines (6 with data), 248 Bytes

m145a 0 128 0 11:38:00 28/04/1989
# Start time=11:38
# First beat=11:40:38.546
# <age-range>: 45-49, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.367,  <RR-high-limit(sec)>: 1.062
# Note: reel-to-reel recording, not flutter-compensated