A "multisite" atrioventricular block.
A 6-year-old child, operated for a perimembranous ventricular septal defect, underwent an electrophysiologic study for the presence of first degree atrioventricular (AV) block and bifascicular block with episodes of type 1 and type 2 second degree AV block. Electrophysiologic study showed a considerable infra-His conduction delay (HV interval 170 ms) and spontaneous phases of infra-His type 1 second degree AV block. During incremental atrial pacing supra-His type 1 second degree AV block and 2:1 infra-His AV block were simultaneously observed and this condition persisted unmodified despite the intravenous injection of atropine. The block distal to the His bundle was considered functional.
Sarubbi
Berardo
B
Division of Pediatric Cardiology, Second University of Naples, Italy. berardo.sarubbi@virgilio.it
Mercurio
Barbara
B
Ducceschi
Valentino
V
Russo
Maria Giovanna
MG
Calabrò
Raffaele
R
D002648:Child; D004452:Echocardiography; D015716:Electrocardiography, Ambulatory; D022062:Electrophysiologic Techniques, Cardiac; D006327:Heart Block / Q000175:diagnosis* / Q000601:surgery; D006329:Heart Conduction System / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D006345:Heart Septal Defects, Ventricular / Q000175:diagnosis / Q000601:surgery; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial