7 lines (6 with data), 254 Bytes

m277b 0 128 0 10:30:00 29/12/1989
# Start time=10:30
# First beat=10:45:55.585
# <age-range>: 55-59, <sex>: Male, <medication>: Moricizine
# <RR-low-limit(sec)>: 0.546,  <RR-high-limit(sec)>: 1.054
# Note: reel-to-reel recording, not flutter-compensated