7 lines (6 with data), 252 Bytes

m066a 0 128 0 20:30:00 09/06/1991
# Start time=20:30
# First beat=20:30:25.359
# <age-range>: 60-64, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.718,  <RR-high-limit(sec)>: 1.515
# Note: recording with a timing signal, flutter-compensated