7 lines (6 with data), 248 Bytes

m006a 0 128 0 10:10:00 20/03/1991
# Start time=10:10
# First beat=10:20:03.320
# <age-range>: 70-74, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.554,  <RR-high-limit(sec)>: 1.007
# Note: reel-to-reel recording, not flutter-compensated