Clinical and electrocardiographic features and results of genetic testing of children with tachy-bradycardia syndrome

Background. Tachy-bradycardia syndrome in adults is often a result of ischemic changes and is detected in 50 % of cases among all patients with sick sinus syndrome. Tachy-bradycardia syndrome has not been studied in children, the genetic mechanisms have not been studied, and the definition of treatment tactics is difficult due to the need to treat both life-threatening bradycardia and tachyarrhythmias in patients.

The aim. To determine the frequency of occurrence of syncope, palpitations and electrocardiographic markers and to study the frequency and representation of genetic mutation associated with the cardiac channelopathies and cardiomyopathies in children with tachy-bradycardia syndrome.

Materials and methods. Eighteen patients with tachy-bradycardia syndrome aged 1 to 17 years (on average 11.3 + 4.97) without structural heart diseases were examined, who underwent a complete cardiological examination with genetic analysis.

Results. 67 % of children in clinical status had syncope, 56 % had palpitations, 39 % had low tolerance of physical activity. A combination of sinus node dysfunction with atrioventricular block I was detected in 56 % of cases, one child had atrioventricular block of I–II degrees. Antiarrhythmic devices were implanted in 6 children, radiofrequency catheter ablation was performed in one, and 7 patients were treated with antiarrhythmic drugs. Variants in various genes associated with channelopathies, arrhythmias or cardiomyopathies were identified in 78 % of patients.

Conclusion. Only 17 % of children with tachy-bradycardia syndrome have not complains. Tachy-bradycardia syndrome with supraventricular tachyarrhythmias may be the first manifestation of a structural pathology of the heart. A genetic study should be included in the examination of children with tachy-bradycardia syndrome, as it allows to diagnose the genetic mechanisms of progressive cardiac conduction diseases, cardiomyopathies, the early manifestations of which are not always detected in children during a standard examination.

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