7 lines (6 with data), 252 Bytes

m232a 0 128 0 10:00:00 03/10/1989
# Start time=10:00
# First beat=10:08:21.554
# <age-range>: 70-74, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.421,  <RR-high-limit(sec)>: 0.828
# Note: recording with a timing signal, flutter-compensated