7 lines (6 with data), 252 Bytes

m188a 0 128 0 12:27:00 19/02/1991
# Start time=12:27
# First beat=12:35:21.218
# <age-range>: 70-74, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.578,  <RR-high-limit(sec)>: 1.093
# Note: recording with a timing signal, flutter-compensated