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Supernormal Conduction in the Left Bundle Branch
Author(s) -
ORETO GIUSEPPE,
SMEETS JOEP L.R.M.,
RODRIGUEZ LUZMARIA,
TIMMERMANS CARL,
WELLENS HEIN J.J.
Publication year - 1994
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.1540-8167.1994.tb01171.x
Subject(s) - medicine , electrical conduction system of the heart , bundle , cardiology , left bundle branch block , bundle of his , bundle branch block , electrocardiography , heart failure , materials science , composite material
Supernormal Conduction. This report describes a patient with tachycardia‐dependent left bundle branch block (LBBB) and atrial extrasystoles, some of which were followed by an unexpectedly narrow QRS complex. His‐bundle recordings and premature atrial stimulation were performed to analyze the mechanism underlying the normalized intraventricular conduction of some of the early atrial impulses. The results suggested the presence of supernormal conduction in the left bundle branch (LBB), because(1) the HV interval was identical in LBBB complexes and in early narrow QRS complexes; (2) during single lest stimulation using different paced atrial cycle lengths, there was a well‐defined range of H 1 , H 2 , intervals resulting in normalization of intraventricular conduction; and (3) atrial pacing with a cycle length of 500 msec resulted in alternation between wide and narrow QRS complexes. These findings rule out alternative mechanisms that could explain the unexpectedly normal intraventricular conduction of early impulses.