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Dual Conduction in a Mahaim Fiber
Author(s) -
STERNICK EDUARDO BACK,
SOSA EDUARDO A.,
SCANAVACCA MAURÍCIO I.,
WELLENS HEIN J.J.
Publication year - 2004
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 - 10.1046/j.1540-8167.2004.04036.x
Subject(s) - medicine , cardiology , tachycardia , left bundle branch block , reentry , ablation , catheter ablation , refractory period , radiofrequency catheter ablation , electrical conduction system of the heart , right bundle branch block , electrocardiography , heart failure
The case of an 8‐year‐old girl with incessant nonsustained left bundle branch block‐like tachycardia refractory to antiarrhythmic drug therapy is reported. Electrophysiologic study revealed the presence of a right‐sided accessory atriofascicular pathway. Episodes of nonsustained tachycardia were found to be based upon a dual response in AV conduction over the Mahaim fiber to one P wave. No reentrant tachycardia could be induced. The arrhythmia was cured by catheter ablation targeting a Mahaim potential at the right lateral tricuspid annulus. The findings can be explained by longitudinal dissociation in a single Mahaim fiber, a fiber distally diverging into two fibers with different conduction times, or (less likely) two closely located Mahaim fibers with different conduction times.