7 lines (6 with data), 251 Bytes

m284a 0 128 0 9:44:00 07/04/1989
# Start time=09:44
# First beat=09:50:38.960
# <age-range>: 60-64, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.492,  <RR-high-limit(sec)>: 0.734
# Note: recording with a timing signal, flutter-compensated