7 lines (6 with data), 253 Bytes

m231b 0 128 0 8:05:00 02/08/1990
# Start time=08:05
# First beat=08:21:08.953
# <age-range>: 60-64, <sex>: Male, <medication>: Moricizine
# <RR-low-limit(sec)>: 0.632,  <RR-high-limit(sec)>: 1.312
# Note: reel-to-reel recording, not flutter-compensated