macroreentry circuit /mak′rōrē·en″trē/ [Gk, makros + L, re, again; Fr, entree, entry] , a relatively large pathway for the reactivation of myocardial tissue by the same impulse. Examples include a reentry circuit that uses one bundle branch for anterograde conduction and another for retrograde conduction to produce the highly malignant bundle branch reentry ventricular tachycardia. Another circuit runs between the top and bottom of the right atrium and produces atrial flutter.
