title: Enhancement of conduction in an accessory pathway by local noncaptured stimuli.
abstract: Subthreshold stimuli have been reported to prolong the refractory period of myocardial tissue. This report presents the first case of reproducible acceleration of a reentrant tachycardia by apparently subthreshold stimuli delivered to the os of the coronary sinus during the atrial refractory period in a child with incessant orthodromic tachycardia utilizing a posteroseptal pathway. Mechanisms by which these stimuli could influence the tachycardia circuit are proposed, and the potential usefulness of this finding for mapping tachyarrhythmias is discussed.
mesh_terms: D002304:Cardiac Pacing, Artificial; D002648:Child; D004562:Electrocardiography; D006801:Humans; D008297:Male; D009434:Neural Pathways / Q000503:physiopathology*; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000503:physiopathology*; D013617:Tachycardia, Supraventricular / Q000503:physiopathology*