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Two‐to‐One AV Block Associated with the Congenital Long QT Syndrome
Author(s) -
PRUVOT ETIENNE,
TORRENTE ANTOINE,
FERRARI GAETANO M.,
SCHWARTZ PETER J.,
GOY JEANJACQUES
Publication year - 1999
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1111/j.1540-8167.1999.tb00647.x
Subject(s) - medicine , refractory period , long qt syndrome , cardiology , heart block , block (permutation group theory) , sinus rhythm , anesthesia , qt interval , electrocardiography , atrial fibrillation , geometry , mathematics
2:1 AV Block in LQTS. Introduction Conduction abnormalities associated with long QT syndrome (LQTS) have been reported as “pseudo 2:1 AV block” due to sinus intervals shorter than ventricular refractoriness. Method and Results: We report the electrophysiologic characteristics of a patient suffering from congenital LQTS with episodes of true 2:1 AV block. Induction of 2:1 infra‐Hisian blocks and return to 1:1 conduction were observed using single atrial and ventricular extrastimuli. The block was located in the Purkinje network but not in the myocardium. Conclusion: The His‐Purkinje system of our LQTS patient displayed dynamic properties with a strong increase in refractoriness for short‐long sequences and a decrease for long‐short sequences that triggered intermittent 2:1 AV blocks.