The total absence of atrial automaticity in a child with sinus node dysfunction.
BACKGROUND
A routine sports evaluation identified constant alternation between a junctional and idioventricular rhythm in a 9-year-old child. During exercise testing, electrography demonstrated that the child was in junctional rhythm without any apparent P waves, and had a reduced increase in heart rate. Endocardial atrial pacing captured the atrium and demonstrated that atrioventricular conduction was normal, but the recovery time of the ectopic rhythm was very long. Three-dimensional electrophysiological mapping revealed 1:1 retrograde homogeneous conduction through the right atrium.


METHODS
Electrocardiography, Holter monitoring, echocardiography, exercise stress testing, atrial pacing, three-dimensional electroanatomical mapping of the right atrium and genetic testing.


METHODS
Sinus node dysfunction.


RESULTS
Pacemaker implantation was postponed until a later stage in the patient's development.
Drago
Fabrizio
F
Arrhythmias Service, Pediatric Cardiology Department, Bambino Gesù Hospital, Rome, Italy. drago@OPBG.net
Fazio
Giovanni
G
Di Pino
Alfredo
A
Silvetti
Massimo Stefano
MS
D016170:Accelerated Idioventricular Rhythm / Q000175:diagnosis*; D002648:Child; D004562:Electrocardiography; D015716:Electrocardiography, Ambulatory; D022062:Electrophysiologic Techniques, Cardiac; D006325:Heart Atria / Q000503:physiopathology*; D006329:Heart Conduction System / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D012849:Sinoatrial Node / Q000503:physiopathology*