7 lines (6 with data), 260 Bytes

m048b 0 128 0 14:00:00 20/07/1990
# Start time=14:00
# First beat=14:00:00.195
# <age-range>: 50-54, <sex>: Female, <medication>: Moricizine
# <RR-low-limit(sec)>: 0.539,  <RR-high-limit(sec)>: 1.046
# Note: recording with a timing signal, flutter-compensated