7 lines (6 with data), 252 Bytes

m244a 0 128 0 15:40:00 11/12/1990
# Start time=15:40
# First beat=15:40:00.601
# <age-range>: 75-79, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.601,  <RR-high-limit(sec)>: 1.242
# Note: recording with a timing signal, flutter-compensated