7 lines (6 with data), 257 Bytes

m243b 0 128 0 10:10:00 14/05/1990
# Start time=10:10
# First beat=10:18:20.750
# <age-range>: 65-69, <sex>: Male, <medication>: Moricizine
# <RR-low-limit(sec)>: 0.554,  <RR-high-limit(sec)>: 1.07
# Note: recording with a timing signal, flutter-compensated