7 lines (6 with data), 254 Bytes

m124b 0 128 0 16:15:00 19/07/1991
# Start time=16:15
# First beat=16:15:00.453
# <age-range>: 60-64, <sex>: Male, <medication>: Moricizine
# <RR-low-limit(sec)>: 0.531,  <RR-high-limit(sec)>: 0.898
# Note: reel-to-reel recording, not flutter-compensated