Association of congenital, diffuse electrical disease in children with normal heart: sick sinus syndrome, intraventricular conduction block, and monomorphic ventricular tachycardia.
BACKGROUND
Rhythm disturbances in children with structurally normal hearts are usually associated with abnormalities in cardiac ion channels. The phenotypic expression of these abnormalities ("channelopathies") includes: long and short QT syndromes, Brugada syndrome, congenital sick sinus syndrome, catecholaminergic polymorphic ventricular tachycardia, Lènegre-Lev disease, and/or different degrees of cardiac conduction disease.


METHODS
The study group consisted of three male patients with sick sinus syndrome, intraventricular conduction disease, and monomorphic sustained ventricular tachycardia. Clinical data and results of electrocardiography, Holter monitoring, electrophysiology, and echocardiography are described.


RESULTS
In all patients, the ECG during sinus rhythm showed right bundle branch block and long QT intervals. First-degree AV block was documented in two subjects, and J point elevation in one. A pacemaker was implanted in all cases due to symptomatic bradycardia (sick sinus syndrome). Atrial tachyarryhthmias were observed in two patients. The common characteristic ventricular arrhythmia was a monomorphic sustained ventricular tachycardia, inducible with ventricular stimulation and sensitive to lidocaine. In one patient, radiofrequency catheter ablation was successfully performed. No structural abnormalities were found in echocardiography in the study group.


CONCLUSIONS
Common clinical and ECG features suggest a common pathophysiology in this group of patients with congenital severe electrical disease.
Iturralde-Torres
Pedro
P
Department of Electrocardiology, National Institute of Cardiology, Ignacio Chávez, Mexico City, Mexico.
Nava-Townsend
Santiago
S
Gómez-Flores
Jorge
J
Medeiros-Domingo
Argelia
A
Colín-Lizalde
Luis
L
Hermosillo
Antonio G
AG
Victoria
Diana
D
Márquez
Manlio F
MF
D054537:Atrioventricular Block / Q000151:congenital* / Q000175:diagnosis*; D002648:Child; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D012804:Sick Sinus Syndrome / Q000151:congenital* / Q000175:diagnosis*; D017180:Tachycardia, Ventricular / Q000151:congenital* / Q000175:diagnosis*