7 lines (6 with data), 251 Bytes

m139a 0 128 0 11:39:00 14/04/1990
# Start time=11:39
# First beat=11:46:10.851
# <age-range>: 50-54, <sex>: Male, <medication>: None
# <RR-low-limit(sec)>: 0.476,  <RR-high-limit(sec)>: 0.89
# Note: recording with a timing signal, flutter-compensated