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2 Cases of New Electrocardiographic Patterns in Patients With Long QT Syndrome
Leonid M Makarov1, Vera N Komolyatova1, Elena V Zaklyazminskaya2
1Federal Scientific Clinical Center for Children and Adolescents of Federal Medico Biological Agency, Moscow, Russia.
Abstract:
Two girls, aged 6 and 16 years, with long QT syndrome and SCN5A mutation in both (long QT syndrome type 3 [LQT3]) were studied. The new electrocardiographic (ECG) patterns of QRS alternans were detected on the sinus rhythm during Holter monitoring in both and also during a bicycle ergometry test in the 16-year-old girl. This pattern is highly likely to indicate increased arrhythmic vulnerability of the heart and risk of cardiac events in patients with LQT3. Take-home message: The cases highlight the importance of targeted visual analysis of ECG and Holter monitoring results and the physician's focus on identifying QRS/T-wave alternans, because automated algorithms are not yet available in commercial ECG and Holter systems.
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