7 lines (6 with data), 251 Bytes

m171a 0 128 0 11:16:00 11/10/1989
# Start time=11:16
# First beat=11:19:13.765
# <age-range>: 65-69, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.46,  <RR-high-limit(sec)>: 1.265
# Note: recording with a timing signal, flutter-compensated