A 28-year-old man underwent transthoracic echocardiography (TTE) following an abnormal electrocardiogram. Parasternal long-axis images revealed a dilated coronary sinus measuring 15 mm × 25 mm (Panel A), raising the possibility of a persistent left superior vena cava (SVC). Bubble contrast TTE using agitated saline injected from the left antecubital vein resulted in opacification of the coronary sinus (*) before filling of the right atrium (Panels B and C, Supplementary materialSupplementary material online, Video S1). This confirmed the presence of a persistent left SVC with drainage into the coronary sinus. Agitated saline injected from the right antecubital vein, unexpectedly, also resulted in filling of the coronary sinus prior to opacification of the right atrium, indicating absence of the right SVC with drainage of the entire upper body venous return to the right atrium via the coronary sinus (Panels D and E, Supplementary materialSupplementary material online, Videos S2 and S3).

中文翻译：

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罕见的持续性左上腔静脉缺如右上腔静脉。

一名28岁的男子在心电图异常后接受了经胸超声心动图检查（TTE）。胸骨旁长轴影像显示15 mm×25 mm的扩张冠状窦（图A），增加了持续左上腔静脉（SVC）的可能性。使用从左肘前静脉注入的搅拌盐水进行的气泡造影剂TTE在充填右心房之前使冠状窦（*）变得不透明（面板B和C，在线补充材料，视频S1）。这证实了存在持久性左SVC并引流至冠状窦。意外地，从右肘前静脉注入搅动的盐水还会导致冠状窦充盈，然后使右房浑浊，