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pacemaker-mediated tachycardiaCardiac pacing Tachycardia seen in atrial tracking pacemakers, which begins with and is sustained by ventricular events conducted retrogradely to the atria; the pacemaker senses retrograde atrial depolarization, then delivers a stimulus to the ventricle, causing depolarization, that again is conducted retrogradely to the atria which, if repeated, causes tachycardia.
A problem of dual-chamber cardiac pacemakers in which tachycardia develops due to improper functioning of the pacemaker. This can be treated by reprogramming the electronic signals to the atrium.
See also: tachycardia