7 lines (6 with data), 257 Bytes

m148b 0 128 0 9:57:00 31/05/1991
# Start time=09:57
# First beat=10:05:13.437
# <age-range>: 70-74, <sex>: Male, <medication>: Moricizine
# <RR-low-limit(sec)>: 0.718,  <RR-high-limit(sec)>: 1.195
# Note: recording with a timing signal, flutter-compensated