7 lines (6 with data), 258 Bytes

m188b 0 128 0 12:59:00 25/03/1991
# Start time=12:59
# First beat=13:07:33.812
# <age-range>: 70-74, <sex>: Male, <medication>: Moricizine
# <RR-low-limit(sec)>: 0.585,  <RR-high-limit(sec)>: 1.179
# Note: recording with a timing signal, flutter-compensated