7 lines (6 with data), 253 Bytes

m212a 0 128 0 13:10:00 21/04/1989
# Start time=13:10
# First beat=13:32:26.164
# <age-range>: 60-64, <sex>: Female, <medication>: None
# <RR-low-limit(sec)>: 0.46,  <RR-high-limit(sec)>: 1.187
# Note: recording with a timing signal, flutter-compensated