title: Unusual QRS morphology on ECG: a rare condition and an interesting response to pacing.
abstract: We present the interesting case of a young man with borderline wide QRS complexes noted on electrocardiogram (ECG). The diagnosis of an unusual form of preexcitation was reached using observations from intracardiac tracings at electrophysiology study. Atrial pacing consistently resulted in further widening of the first conducted QRS complex, and the physiology underlying this unusual finding is explored.
authors.affiliation: Division of Cardiology, Boston Veterans Affairs Healthcare System, Massachusetts, USA. lgula@uwo.ca
authors.forename: Lorne J
authors.initials: LJ
authors.lastname: Gula
authors.forename: Robert E
authors.initials: RE
authors.lastname: Eckart
authors.forename: George J
authors.initials: GJ
authors.lastname: Klein
authors.forename: Adelqui
authors.initials: A
authors.lastname: Peralta
mesh_terms: D000328:Adult; D002304:Cardiac Pacing, Artificial / Q000379:methods; D003937:Diagnosis, Differential; D004562:Electrocardiography; D006801:Humans; D008297:Male; D011226:Pre-Excitation Syndromes / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy