7 lines (6 with data), 258 Bytes

m144b 0 128 0 16:37:00 28/03/1991
# Start time=16:37
# First beat=16:45:21.671
# <age-range>: 50-54, <sex>: Male, <medication>: Moricizine
# <RR-low-limit(sec)>: 0.609,  <RR-high-limit(sec)>: 1.304
# Note: recording with a timing signal, flutter-compensated