Omer Seham O, Alhabshan Fahad M, Jijeh Abdulraouf M Z, Caimbon Natalia C, Enriquez Carmelita C, Männer Jörg, Yelbuz Talat Mesud
Department of Cardiac Sciences King Abdulaziz Cardiac CenterMinistry of National Guard Health Affairs Riyadh Saudi Arabia.
King Abdullah International Medical Research Center (KAIMRC) Riyadh Saudi Arabia.
J Am Heart Assoc. 2021 Aug 3;10(15):e019334. doi: 10.1161/JAHA.120.019334. Epub 2021 Jul 19.
Background The pathogenesis of transposition of the great arteries (TGA) as a congenital heart defect of the outflow tract with discordant ventriculoarterial connections remains an enigma. TGA usually have parallel great arteries suggesting that deficient torsion of the embryonic arterial heart pole might cause discordant ventriculoarterial connections. It has been speculated that deficient elongation of the embryonic outflow tract might prevent its normal torsion resulting in TGA. The aim of our study was to clarify whether the intrapericardial portions of the great arteries in human patients with TGA might be indeed shorter than in normal hearts. Methods and Results Thirty-four newborns with simple TGA and 35 newborns with normal hearts were analyzed by using images of the outflow tract in their echocardiograms and the following defined lengths of the great arteries were measured: aortic length 1, (AoL-1) and aortic length 2 (AoL-2) = distance between left and right aortic valve level and origin of the brachiocephalic artery, respectively. Pulmonary trunk length 1 (PTL-1) and pulmonary trunk length 2 (PTL 2) = distance between left and right pulmonary valve level and origin of left and right pulmonary artery, respectively. All measurements of the AoL were significantly shorter in TGA compared to normal hearts (AoL-1: 1.6±0.2 versus 2.05±0.1; <0.0001; AoL-2: 1.55±0.2 versus 2.13±0.1; <0.0001). With regard to the pulmonary trunk (PT), PTL-1 and PTL-2 were found to be shorter and longer, respectively, in TGA compared with normal hearts, reflecting the differences in the spatial arrangement of the PT between the 2 groups as in TGA the PT is showing a mirror image of the normal anatomy. However, the overall length of the PT between the 2 groups did not differ. Conclusions Our data demonstrate that, compared with normal newborns, the ascending aorta is significantly shorter in newborns with TGA whereas the overall length of the PT does not differ between the 2 groups. This finding is in accord with the animal model-based hypothesis that TGA may result from a growth deficit at the arterial pole of the embryonic heart.
背景 大动脉转位（TGA）作为一种具有心室动脉连接不一致的先天性流出道心脏缺陷，其发病机制仍是一个谜。TGA通常具有平行的大动脉，这表明胚胎动脉心极的扭转不足可能导致心室动脉连接不一致。据推测，胚胎流出道伸长不足可能会阻止其正常扭转，从而导致TGA。我们研究的目的是阐明患有TGA的人类患者的大动脉心包内部分是否确实比正常心脏短。
方法与结果 利用34例单纯性TGA新生儿和35例正常心脏新生儿的超声心动图流出道图像进行分析，并测量以下定义的大动脉长度：主动脉长度1（AoL-1）和主动脉长度2（AoL-2），分别为左、右主动脉瓣水平与头臂动脉起源之间的距离。肺动脉干长度1（PTL-1）和肺动脉干长度2（PTL-2），分别为左、右肺动脉瓣水平与左、右肺动脉起源之间的距离。与正常心脏相比，TGA中所有AoL测量值均显著缩短（AoL-1：1.6±0.2对2.05±0.1；<0.0001；AoL-2：1.55±0.2对2.13±0.1；<0.0001）。关于肺动脉干（PT），与正常心脏相比，TGA中PTL-1较短，PTL-2较长，这反映了两组之间PT空间排列的差异，因为在TGA中PT呈现出正常解剖结构的镜像。然而，两组之间PT的总长度没有差异。
结论 我们的数据表明，与正常新生儿相比，患有TGA的新生儿升主动脉明显较短，而两组之间PT的总长度没有差异。这一发现与基于动物模型的假说一致，即TGA可能是由胚胎心脏动脉极的生长缺陷引起的。
