7 lines (6 with data), 252 Bytes

m294a 0 128 0 10:15:00 05/03/1990
# Start time=10:15
# First beat=10:15:00.140
# <age-range>: 70-74, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.625,  <RR-high-limit(sec)>: 1.132
# Note: recording with a timing signal, flutter-compensated