7 lines (6 with data), 253 Bytes

m074a 0 128 0 9:50:00 06/11/1990
# Start time=09:50
# First beat=09:58:20.273
# <age-range>: 70-74, <sex>: Female, <medication>: None
# <RR-low-limit(sec)>: 0.601,  <RR-high-limit(sec)>: 1.015
# Note: recording with a timing signal, flutter-compensated