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Prevention of Tachycardia Initiation by Programmed Stimulation
Author(s) -
BEGEMANN MALCOLM J.S.,
BENNEKERS JOHAN H.,
KINGMA J. HERRE,
Lie K.I.
Publication year - 1990
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1111/j.1540-8167.1990.tb01703.x
Subject(s) - medicine , cardiology , tachycardia , refractory period , ventricle , stimulation , stimulus (psychology) , ventricular tachycardia , effective refractory period , electrophysiology , depolarization , anesthesia , psychology , psychotherapist
A 20‐year‐old female with a left‐sided concealed atrioventricular accessory pathway was studied during programmed stimulation to investigate the mechanisms of prevention of tachycardia by timed stimulation of the ventricle after a tachycardia initiating atrial extrastimulus. After the atrial tachycardia initiation zone was determined, the prvention zone of the ventricular stimulus was determined for each initiating interval. Two different prevention mechanisms were found, one whereby the ventricular depolarization was blocked retrogradely in the accessory pathway and another whereby the ventricular depolarization was conducted over the accessory pathway to the atrium but subsequently blocked anterogradely in the AV node. The preventive zone timed from the last ventricular complex to the ventricular stimulus was always greater than 30 msec whereby the minimum preventive internal was determined by the ventricular refractory period. This could be of value when such a preventive algorithm is incorporated into a dual‐chamber antitachycardia pacemaker. Knowing the exact mechanisms by which the prevention occurs allows one to predict how tachycardia can be prevented when the atrial extra beat originates from a different site and when the parameters of the heart are changed due to changes in antonomic tone or catecholamine level.