每日一题_2023.07.05

A 5-month-old girl is brought to the emergency department by her parents because she is “turning blue.” She is cyanotic, weak, and dyspneic. Her parents state that she has experienced similar episodes in the past, but never this severe. Physical examination reveals the lungs are clear to auscultation, with no wheezing, rales, or rhonchi. Cardiac examination reveals a regular rate and rhythm, normal S1, single S2, a grade III rough systolic murmur at the left sternal border in the third intercostal space, and a palpable right ventricular lift. Echocardiography demonstrates unusual positioning of the aorta, which overrides both the left and right ventricles in the long axis view. In this condition, the primary developmental defect occurs in which portion of the primitive heart?

一个5个月大的女婴被父母带到急诊室，因为她“变成了青色”。她有青紫症、虚弱和呼吸困难。她的父母说她以前也有类似的发作，但从未这么严重过。体格检查显示肺部听诊为清晰，没有哮鸣音、湿罗音或干罗音。心脏检查发现心率和节律规律，正常的S1，单一的S2，在第三肋间隙的左胸骨边缘有一个Ⅲ级粗糙性收缩期杂音，并可以触及右室扩大。超声心动图显示主动脉异常位置，主动脉在长轴视图中覆盖了左室和右室。在这种情况下，原始心脏的主要发育缺陷出现在哪个部分？

(A) Bulbus cordis动脉球部分

(B) Conal septum动脉漏斗部分

(C) Left and right horns of the sinus venosus 心窦左、右角部分

(D) Primitive atria原始心房

(E) Primitive ventricle原始心室

答案解析：

这个病人患有法洛四联症(TOF)。TOF是最常见的先天性紫绀型病变，其特征是四种先天性心脏异常:(1)肺动脉瓣狭窄，(2)室间隔缺损，(3)覆盖(右弓)主动脉，(4)右心室肥厚(由于流出道梗阻)。病情的严重程度由发绀的程度决定，而发绀的程度又最依赖于肺动脉狭窄的程度。在最严重的病例中，TOF患儿在出生时发绀，但大多数TOF患儿在4 ~ 6个月时出现反复发作的低氧血症和发绀。原发性发育缺陷是圆锥隔前侧和头侧的异常移位，导致主动脉扩大和肺动脉阻塞。

正确答案：B