ВЫЯВЛЕНИЕ И ДИСПАНСЕРНОЕ НАБЛЮДЕНИЕ ДЕТЕЙ С СИНДРОМОМ УДЛИНЕННОГО ИНТЕРВАЛА QT

Aim To assess the diagnostic accuracy of long QT syndrome in children and to estimate the results of the follow-up.Methods High-risk groups of children with bradycardia less than the second percentile and/or a family history of sudden death syndrome, and children with syncope diagnosed with the ECG testing were included in the study. All patients underwent routine medical examination, molecular genetic testing and were followed-up for 3,5–10 years.Results The majority of children haves transient corrected QT prolongation secondary to therapy, requiring ECG monitoring. High-risk group screening reports higher rates of idiopathic LQTS. ECG testing shows its efficiency among asymptomatic children with a normal heart rate. Patients present with syncope at the outpatient settings require the exclusion of a wide range of diseases, both congenital and acquired heart disease. The clinical status of the examined patients does not always correspond to the known LQTS variants. Molecular genetic analysis provides relevant information on the genetic heterogeneity of the disease, including new mutations, both pathological and beneficial ones.Conclusion Regardless of the presence or absence of molecular genetic confirmation of LQTS, beta blocker therapy in some cases combined with implanted cardioverterdefibrillator prevents the development of the adverse events in the long-term period and ensures normal emotional, intellectual and physical development.Цель Изучить эффективность диагностики синдрома удлиненного интервала QT (СУИQT) у детей и результаты наблюдения детей по данным катамнеза.Материалы и методы Проведено обследование детей двух групп риска – новорожденных с брадикардией менее 2 перцентиля и семейным анамнезом внезапной смерти, и детей с синкопе с помощью ЭКГ-скрининга, комплексного обследования выделенных групп, и наблюдение детей в течение 3,5–10 лет .Результаты Установлено, что в периоде новорожденности значительная часть детей имеет преходящее вторичное удлинение корригированного QT, что требует ЭКГ-контроля после лечения. Обследование детей из групп риска имеет большую вероятность выявления пациентов с идиопатическим СУИQT, тогда как у бессимптомных детей с нормальной частотой сердечного ритма выявление больных возможно только при проведении ЭКГ-скрининга. У пациентов с синкопе на амбулаторном этапе обследования необходимо исключение широкого спектра заболеваний, включая врожденные и приобретенные болезни сердца. Клинический статус наблюдаемых больных не всегда соответствует известным вариантам СУИQT.Заключение Независимо от наличия или отсутствия молекулярно-генетического подтверждения диагноза терапия бета-адреноблокаторами, и в ряде случаев ее сочетание в комбинации с имплантированным кардиовертером-дефибриллятором обеспечивает в течение длительного времени клиническую стабильность пациентов, удовлетворительные темпы эмоционального, интеллектуального и физического развития, предотвращает развитие сердечных событий с неблагоприятным исходом

Beta1-Adrenoceptor Polymorphism Predicts Flecainide Action in Patients with Atrial Fibrillation

BACKGROUND: Antiarrhythmic action of flecainide is based on sodium channel blockade. Beta(1)-adrenoceptor (beta(1)AR) activation induces sodium channel inhibition, too. The aim of the present study was to evaluate the impact of different beta(1)AR genotypes on antiarrhythmic action of flecainide in patients with structural heart disease and atrial fibrillation. METHODOLOGY/PRINCIPAL FINDINGS: In 145 subjects, 87 with atrial fibrillation, genotyping was performed to identify the individual beta(1)AR Arg389Gly and Ser49Gly polymorphism. Resting heart rate during atrial fibrillation and success of flecainide-induced cardioversion were correlated with beta(1)AR genotype. The overall cardioversion rate with flecainide was 39%. The Arg389Arg genotype was associated with the highest cardioversion rate (55.5%; OR 3.30; 95% CI; 1.34-8.13; p = 0.003) compared to patients with Arg389Gly (29.5%; OR 0.44; 95% CI; 0.18-1.06; p = 0.066) and Gly389Gly (14%; OR 0.24; 95% CI 0.03-2.07; p = 0.17) variants. The single Ser49Gly polymorphism did not influence the conversion rate. In combination, patients with Arg389Gly-Ser49Gly genotype displayed the lowest conversion rate with 20.8% (OR 0.31; 95% CI; 0.10-0.93; p = 0.03). In patients with Arg389Arg variants the heart rate during atrial fibrillation was significantly higher (110+/-2.7 bpm; p = 0.03 vs. other variants) compared to Arg389Gly (104.8+/-2.4 bpm) and Gly389Gly (96.9+/-5.8 bpm) carriers. The Arg389Gly-Ser49Gly genotype was more common in patients with atrial fibrillation compared to patients without atrial fibrillation (27.6% vs. 5.2%; HR 6.98; 95% CI; 1.99-24.46; p<0.001). CONCLUSIONS: The beta(1)AR Arg389Arg genotype is associated with increased flecainide potency and higher heart rate during atrial fibrillation. The Arg389Gly-Ser49Gly genotype might be of predictive value for atrial fibrillation

Genetic tests for low-and middle-income countries: a literature review

The aim of this review is to describe a series of ten genetic diseases with Mendelian inheritance pattern in people of low-or middle-income countries, which can be easily identified with simple and affordable methods. Recent information shows that although genetic diseases account for more than 10% of infant mortality in such countries, testing, counseling, and treatment of genetic diseases is not a priority. The selection criteria for the genetic tests that are discussed in this review are: i) the frequency of the genetic disease in the general population, ii) the cost and ease of execution, and iii) the report of validated methods in the literature for the diagnosis of these diseases. The goal is to promote diagnosis of genetic diseases at low-cost and with relative ease, thereby enabling appropriate treatments, reducing mortality, and preventing genetic diseases in high-risk families