李×,男,6个月。以食少纳差一周为主诉就诊。足月顺产第一胎。母健,妊娠期未患过任何疾病,未服用任何药物。妊娠末期曾做产前检查发现胎心率缓。患儿生后生长发育正常,无其它病史可询,否认反复晕厥史。生后3个月时因咳嗽曾于当地医院就诊发现心率过缓,疑诊“先心病”,但未做心电图检查。家族无类似病史。体检:发育营养中等,体重6公斤,心界不大,心尖部可 Lee ×, male, 6 months. Eat less appetite week for chief complaint. Full-term first-born fetus. Mother health, not suffering from any disease during pregnancy, did not take any drugs. Have done prenatal examination at the end of pregnancy found fetal heart rate slow. Children with normal growth and development after birth, no other history may be asked to deny the history of repeated syncope. 3 months after birth due to cough had been seen in the local hospital heart rate was too slow, suspected “congenital heart disease”, but did not make ECG. No similar family history. Physical examination: development of moderate nutrition, weight 6 kg, the heart is not big, apex can be