7 lines (6 with data), 248 Bytes

m291a 0 128 0 10:08:00 09/07/1991
# Start time=10:08
# First beat=10:08:00.539
# <age-range>: 60-64, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.585,  <RR-high-limit(sec)>: 1.031
# Note: reel-to-reel recording, not flutter-compensated