7 lines (6 with data), 258 Bytes

m275b 0 128 0 16:03:00 22/03/1991
# Start time=16:03
# First beat=16:10:11.296
# <age-range>: 70-74, <sex>: Male, <medication>: Moricizine
# <RR-low-limit(sec)>: 0.531,  <RR-high-limit(sec)>: 1.234
# Note: recording with a timing signal, flutter-compensated