Enhancement of conduction in an accessory pathway by local noncaptured stimuli
R Rothschild,
WG Stevenson,
T Klitzner,
and
J Weiss
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.
