title: Paroxysmal supraventricular tachycardia with unusual induction. Concealed reentry or automaticity?
abstract: In a patient with documented paroxysmal supraventricular tachycardia, earlier atrial extrastimuli consistently induced His-ventricle (H-V) block and "atrioventricular junctional" beats, which were always followed by an echo or paroxysmal supraventricular tachycardia. In "atrioventricular junctional" beats, a V wave was preceded by an H deflection with the same intervals as that of the sinus beat. As for the underlying mechanism of paroxysmal supraventricular tachycardia, two possibilities were considered: (1) concealed atrioventricular nodal reentry, and (2) "triggered automaticity."
mesh_terms: D000328:Adult; D001283:Atrioventricular Node / Q000503:physiopathology; D002036:Bundle of His / Q000503:physiopathology; D004562:Electrocardiography; D004594:Electrophysiology; D005260:Female; D006327:Heart Block / Q000503:physiopathology; D006352:Heart Ventricles; D006801:Humans; D013614:Tachycardia, Paroxysmal / Q000503:physiopathology*