Whats your interpretation ??? Scroll down for answer. 

References: 

Brady WJ, Glass III GF. Cardiac Rhythm Disturbances. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 9e New York, NY: McGraw-Hill