Abstract：
The authors describe a case of fetal isolated right atrial enlargement or IDRA (idiopathic dilatations of the right atrium) evident in third trimester, complicated by arrhythmia in the female infant during the 1° month of life with ECG diagnosis of Wolf-Parkinson-White syndrome (WPW). The eldest sister died at 6 years because of an arrhythmia with the same diagnosis of WPW. The review of the literature on IDRA frequently shows a familial genetic aggregation. The pathogenetic mechanism underlying the dilation of the right atrium could consist of a myopathy or electrical conduction disorder. The exclusive involvement of the right atrium may be due to the increased pressure in the fetal right atrium. On the basis of our case and after review of the literature, we must be careful in defining as physiological the enlargement of the right fetal atrium in the third trimester of pregnancy. The ultrasound sign of IDRA may be a fetal prodrome of SIDS (sudden infant death syndrome).
摘要：
作者描述了在妊娠晚期明显的胎儿孤立的右心房扩大或IDRA（特发性右心房扩张）的病例。女性婴儿在1个月的生命中并发心律失常，心电图诊断为Wolf-Parkinson-White综合征（WPW）。大姐因心律失常于6年死亡，与WPW的诊断相同。关于IDRA的文献综述经常显示家族遗传聚集。右心房扩张的发病机制可能由肌病或电传导障碍组成。右心房的唯一受累可能是由于胎儿右心房的压力增加。在我们的案例的基础上，经过文献回顾，我们必须小心将妊娠晚期右胎心房增大定义为生理性。IDRA的超声征象可能是SIDS（婴儿猝死综合征）的胎儿前驱症状。
