7 lines (6 with data), 258 Bytes

m023b 0 128 0 11:30:00 05/09/1990
# Start time=11:30
# First beat=11:30:00.367
# <age-range>: 70-74, <sex>: Male, <medication>: Moricizine
# <RR-low-limit(sec)>: 0.476,  <RR-high-limit(sec)>: 1.031
# Note: recording with a timing signal, flutter-compensated