Efficacy and Safety of Sotalol in Children With Arrhythmia

Inclusion Criteria: 1. Age 0 day to 14 year-old 2. Diagnosis of tachycardia (paroxysmal supraventricular tachycardia, paroxysmal atrial tachycardia, ventricular tachycardia, idiopathic ventricular tachycardia, premature ventricular contraction) and had an episode within 3 months; Premature Ventricular Contractions (PVC) (total 10000 times/d, or\>5000 times/d with multiple source PVC, or total \> 3000 times/d but with paired PVC+ multiple source PVC, or ventricular tachycardia); 3. Although PVC≤ 10000 times/d, but there are obvious symptoms such as palpitation, chest tightness, fatigue, dizziness and other symptoms that need improvement. 4. Signed informed consent before the trial 5. Good compliance Exclusion Criteria: 1. Heart failure that is ineffective in conventional treatment; 2. Left ventricular ejection fraction (LVEF) ≤ 50%; 3. Suffering from bronchial asthma; 4. Resting sinus heart rate (HR) in newborns \<90 bpm; -8 yrs \<80 bpm; ≥ 8 yrs \<60 bpm; 5. Corrected QT Interval (QTc) ≥ 450ms; 6. II ° -III ° atrioventricular block (AVB); 7. Severe liver, renal dysfunction, acute myocardial infarction, acute myocarditis, electrolyte imbalance have not been corrected; 8. The child has undergone major surgery in the past 4 weeks; 9. The child has participated in other clinical trials in the past 4 weeks; 10. The child has digestive, nervous, circulatory, kidney or liver disease