title: Second degree entrance block in intermittent ventricular parasystole.
abstract: In a 21-year-old healthy man, there may be a second degree entrance block occasionally of 2:1 nature resulting in intermittent ventricular parasystole. The refractory period of the ventricular-ectopic (V-E) junction in this case was markedly longer than the ventricular muscle except the V-E junction, but much shorter than the whole length of the parasystolic cycle.
mesh_terms: D000328:Adult; D001145:Arrhythmias, Cardiac / Q000209:etiology* / Q000503:physiopathology; D004562:Electrocardiography; D006327:Heart Block / Q000150:complications* / Q000503:physiopathology; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male