title: Arrhythmias in the coronary-care unit. IV. Physiologic bases of paroxysmal tachycardia-dependent bundle branch block.
abstract: Paroxysmal BBB may be either tachycardia-dependent which is referred to as "phase 3 block" or bradycardia-dependent, referred to as "phase 4 block." Tachycardia-dependent BBB is related to prolonged recovery. Bradycardia-dependent BBB is related to hypopolarization and SDD. These fundamental electrophysiological properties aid in understanding of transient BBB occurring during an acute MI.
mesh_terms: D002037:Bundle-Branch Block / Q000503:physiopathology*; D004562:Electrocardiography; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013614:Tachycardia, Paroxysmal / Q000503:physiopathology*