7 lines (6 with data), 247 Bytes

m265a 0 128 0 11:15:00 22/12/1990
# Start time=11:15
# First beat=11:16:53.796
# <age-range>: 70-74, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.57,  <RR-high-limit(sec)>: 1.781
# Note: reel-to-reel recording, not flutter-compensated