7 lines (6 with data), 252 Bytes

m050a 0 128 0 15:15:00 06/11/1990
# Start time=15:15
# First beat=15:15:00.515
# <age-range>: 60-64, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.695,  <RR-high-limit(sec)>: 1.375
# Note: recording with a timing signal, flutter-compensated