title: Atrioventricular block after reciprocating atrioventricular junctional tachycardia.
abstract: Short runs of symptomatic atrioventricular (A-V) block occurred after spontaneous cessation of reciprocating A-V junctional tachycardia in a patient with right bundle branch block, normal H-V interval and sinus nodal dysfunction. These episodes were characterized by long (more than 1 sec) P-P intervals during which the A deflections were not followed by His bundle electrograms. Three possible explanations are: (1) a posttachycardia-induced period of abnormally prolonged A-V nodal refractoriness; (2) pseudo-A-V block produced by concealed A-V junctional tachycardia, or (3) bradycardia-dependent (phase 4) A-V block at the "upper" His bundle, above the site from which the H deflection was recorded.
mesh_terms: D001283:Atrioventricular Node / Q000503:physiopathology; D001919:Bradycardia / Q000150:complications; D002037:Bundle-Branch Block / Q000503:physiopathology; D004562:Electrocardiography; D006327:Heart Block / Q000209:etiology / Q000503:physiopathology*; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013610:Tachycardia / Q000150:complications / Q000503:physiopathology*