7 lines (6 with data), 247 Bytes

m151a 0 128 0 11:35:00 04/05/1988
# Start time=11:35
# First beat=11:54:56.679
# <age-range>: 60-64, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.57,  <RR-high-limit(sec)>: 1.039
# Note: reel-to-reel recording, not flutter-compensated