7 lines (6 with data), 248 Bytes

m173a 0 128 0 13:54:00 28/04/1990
# Start time=13:54
# First beat=13:54:40.703
# <age-range>: 55-59, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.429,  <RR-high-limit(sec)>: 1.164
# Note: reel-to-reel recording, not flutter-compensated