7 lines (6 with data), 254 Bytes

m125b 0 128 0 15:25:00 05/06/1991
# Start time=15:25
# First beat=15:30:12.320
# <age-range>: 70-74, <sex>: Male, <medication>: Moricizine
# <RR-low-limit(sec)>: 0.656,  <RR-high-limit(sec)>: 1.296
# Note: reel-to-reel recording, not flutter-compensated