排除标准 Exclusion Criteria

• 患者年龄等于或大于21岁
• 患者家族史中具有40岁一下的怀疑或者确认的心源性的猝死（The patient has a family history of premature (less than 40 years old) sudden death of presumed or established cardiac origin）.
• 患者家族史具有QT间隔延长综合征
• 患者家族史具有心肌症
• 患者显示具有心肌炎病史
• 患者具有晕厥、晕厥前期或痉挛史
• 患者自身认为存在持续心动过速的问题
• 患者存在心悸之外的其他心脏症状
• 患者已在儿科心脏专家的就诊中通过心脏检查确认了异常
• 患者具有异常心电图（除关联的室性早搏以外）
• 患者具有延长的QT间期

临床协议说明

For this algorithm, "Time 0" is the initial evaluation by a pediatric cardiologist. The committee debated extensively about the need for 24-hour ambulatory ECG monitoring, echocardiography, and exercise testing. Thus, these were considered class II tests. Use of these studies is influenced by factors such as the patient's age, frequency and intensity of palpitations, and probability of an associated viral illness or other systemic diseases.