7 lines (6 with data), 258 Bytes

m143b 0 128 0 10:20:00 18/05/1990
# Start time=10:20
# First beat=10:28:21.570
# <age-range>: 65-69, <sex>: Male, <medication>: Moricizine
# <RR-low-limit(sec)>: 0.578,  <RR-high-limit(sec)>: 1.062
# Note: recording with a timing signal, flutter-compensated