7 lines (6 with data), 248 Bytes

m270a 0 128 0 14:06:00 11/05/1989
# Start time=14:06
# First beat=14:22:52.484
# <age-range>: 60-64, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.609,  <RR-high-limit(sec)>: 1.265
# Note: reel-to-reel recording, not flutter-compensated