Comstock C H
Obstet Gynecol. 1987 Aug;70(2):255-9.
Cardiac position and axis were evaluated by ultrasound in 183 normal fetuses; both position and axis were found to be constant throughout gestational life. In the four-chamber view of the fetal heart, the normal axis lies at a 45 degree angle (range 22-75 degrees) to the left of an anteroposterior line drawn from the spine to the anterior chest wall. The normal position of the posterior portion of the heart can also be defined. The axis or position of the heart deviated from the established normal range in 15 cases, the outcome of which is discussed. Abnormal axis was associated with 50% mortality; abnormal position with 81% mortality. Deviation from the normal position of the fetal heart should initiate a search for an intrathoracic mass, whereas an abnormal axis is an indication for fetal echocardiography. Axis and position of the fetal heart are easily evaluated during a standard obstetric scan.
通过超声对183例正常胎儿的心脏位置和轴进行了评估；发现整个孕期心脏位置和轴均保持恒定。在胎儿心脏的四腔心视图中，正常轴与从脊柱到前胸壁的前后线左侧呈45度角（范围为22 - 75度）。心脏后部的正常位置也可确定。15例胎儿的心脏轴或位置偏离既定正常范围，对其结果进行了讨论。轴异常与50%的死亡率相关；位置异常与81%的死亡率相关。胎儿心脏位置偏离正常应开始寻找胸腔内肿块，而轴异常则是胎儿超声心动图检查的指征。在标准产科扫描期间很容易评估胎儿心脏的轴和位置。
