title: Syncope and preexcitation: a case of a Kent and fasciculoventricular Mahaim fibers.
abstract: A case involving an 8-year-old girl with syncope and preexcitation on a surface electrocardiogram (ECG) that was suggestive of Wolff-Parkinson-White syndrome is presented. An intracardiac electrophysiologic study revealed a posteroseptal bidirectionally conducting Kent fiber. Radiofrequency ablation of the Kent fiber was successful, but the patient had a residual short His-ventricular (HV) interval and a new preexcitation pattern. Atrial extra stimuli and ventricular pacing revealed a fixed, preexcited QRS. Nodal block and loss of preexcitation was provoked with adenosine. The surface QRS and electrophysiologic features are consistent with a left septal fasciculoventricular Mahaim fiber.
authors.affiliation: Division of Cardiology, Westchester Medical Center, New York Medical Center, Valhalla, New York 10595, USA.
authors.forename: C
authors.initials: C
authors.lastname: Sorbera
authors.forename: M
authors.initials: M
authors.lastname: Cohen
authors.forename: P
authors.initials: P
authors.lastname: Woolf
mesh_terms: D002648:Child; D004562:Electrocardiography; D005260:Female; D006801:Humans; D011226:Pre-Excitation Syndromes / Q000150:complications* / Q000503:physiopathology; D011227:Pre-Excitation, Mahaim-Type / Q000150:complications / Q000503:physiopathology; D013575:Syncope / Q000150:complications* / Q000503:physiopathology