7 lines (6 with data), 252 Bytes

m293a 0 128 0 15:25:00 11/04/1991
# Start time=15:25
# First beat=15:25:02.804
# <age-range>: 50-54, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.546,  <RR-high-limit(sec)>: 1.078
# Note: recording with a timing signal, flutter-compensated