 7. ECG showed abnormal rhythm, conduction and form, such as complete left bundle branch block, 2 degree heart block, PR interval 250ms, experienced myocardial infarction in 6 months. Risks leading to prolonged QT interval or arrhythmia, such as heart failure, hypokalemia, congenital long QT, long QT family history or sudden death under 40 years old in first degree relatives 12 lead electrocardiogram QT interval correlated to Bazetts QTcB 450ms. 