7 lines (6 with data), 258 Bytes

m164b 0 128 0 10:55:00 14/12/1990
# Start time=10:55
# First beat=10:55:11.398
# <age-range>: 50-54, <sex>: Male, <medication>: Moricizine
# <RR-low-limit(sec)>: 0.429,  <RR-high-limit(sec)>: 0.859
# Note: recording with a timing signal, flutter-compensated