Patterns of atrioventricular conduction in children.
In this study, intracardiac electrograms were performed in 20 children--ranging in age from eight months to 18 years and without evidence of conduction disturbances on the scalar electrocardiogram--to determine the normal conduction patterns, response to atrial pacing, and values of refractory periods. Atrial pacing--18 cases--induced a prolongation al AH on increasing heart rates in all; 11 developed Wenckebach block proximal to the bundle of His at the mean pacing rate of 224 per minute +/- 45 (1 S.D.). Refractory periods were shorter than in adults. Study of the pattern of A-V conduction revealed three types of response: (1) the atrium was the limiting structure in 11 cases; (2) the delay occurred in the A-V node only in four cases; and (3) the delay occurred both in the A-V node and His-Purkinje system. This response was observed in one case only.
D000293:Adolescent; D000367:Age Factors; D001145:Arrhythmias, Cardiac / Q000503:physiopathology; D016275:Atrial Function; D001283:Atrioventricular Node / Q000502:physiology; D002036:Bundle of His / Q000502:physiology; D002037:Bundle-Branch Block / Q000503:physiopathology; D006328:Cardiac Catheterization; D002648:Child; D002675:Child, Preschool; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000502:physiology*; D006330:Heart Defects, Congenital / Q000503:physiopathology; D006339:Heart Rate; D006801:Humans; D007223:Infant; D008297:Male; D010138:Pacemaker, Artificial; D011930:Reaction Time