[Hereditary cardiac arrhythmia]

Although most of arrhythmia are secondary to cardiac disease, for example, ischemic heart disease and valvular heart disease, some types of arrhythmia are hereditary. Long QT syndrome (LQTS) is a hereditary cardiac disorder that causes syncope and sudden death from ventricular tachyarrhythmia. A boy eight years old, who had the familial history of LQTS in his sister and mother, admitted in our hospital. He had some episodes of syncope and markedly prolonged QT interval of 0.58 seconds in electrocardiogram. After follow-up of 12 years, he died suddenly because of interrupted medication including beta-blocker. Another patient with ventricular tachyarrhythmia also admitted. His family tree in which three young men died suddenly, revealed hereditary cardiomyopathy. Hereditary cardiac arrhythmia as shown the above clinically important because of prevention from sudden death, especially in young patients.