Larroussi Leila, Badhwar Nitish
Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, University of California, San Francisco, San Francisco, CA, USA.
Section of Cardiac Electrophysiology, Division of Cardiology, Department of Medicine, University of California, San Francisco, San Francisco, CA, USA; UCSF Medical Center, 500 Parnassus Avenue, MUE-431, San Franicsco, CA 94143, USA.
Card Electrophysiol Clin. 2016 Mar;8(1):51-5. doi: 10.1016/j.ccep.2015.10.003. Epub 2016 Jan 8.
This report illustrates an interesting case of atrioventricular nodal reentrant tachycardia that presented with 2 different ventricular cycle lengths due to a 2:1 block in the lower common pathway. At the induction of the tachycardia, a long-short sequence above the His creates a phase 3 block resulting in a 2:1 conduction in the lower common pathway. A premature ventricular contraction, by retrograde penetration of the His, eliminates the long-short sequence and brings the conduction back to 1:1.
