7 lines (6 with data), 258 Bytes

m283b 0 128 0 10:26:00 04/06/1991
# Start time=10:26
# First beat=10:31:03.523
# <age-range>: 45-49, <sex>: Male, <medication>: Moricizine
# <RR-low-limit(sec)>: 0.484,  <RR-high-limit(sec)>: 0.812
# Note: recording with a timing signal, flutter-compensated