Bicuspid Aortic Valve Associated With Persistent Left and Absent Right Superior Vena Cava

A bicuspid aortic valve is the most common congenital cardiovascular anomaly, occurring in 1% to 2% of the population. It usually occurs in isolation but is associated with other abnormalities in 20% of cases. The most common abnormalities are coarctation of the aorta (reported in 20%-85% of cases of coarctation of the aorta) and patent ductus arteriosus. There is also a high prevalence of aortic root enlargement in patients with bicuspid aortic valve that occurs irrespective of altered hemodynamics or age and may progress to aneurysm formation or rupture.1

Other coexisting lesions that have been reported are ventricular septal defect, aortic sinus aneurysm, anomalous origin of the right coronary artery from the left aortic sinus of Valsalva, and congenital ostial left main coronary artery stenosis.1, 2 Although the high incidence of coexisting abnormalities is related to bicuspid aortic valve; so far, there is no study that has reported association of this abnormality with persistent left and agenesis of the right superior vena cava.

Therefore, we report the first case in which bicuspid aortic valve is combined with persistent left and absent right superior vena cava. In addition, the importance of contrast transesophageal echocardiography (TEE) in the differential diagnosis of this cardiothoracic anomaly is also discussed.

A 30-year-old man was admitted to the intensive care unit because of multiple-organ trauma involving multiple rib fractures with bilateral hemopneumothorax. To delineate possible traumatic disruption of the thoracic aorta a, TEE examination was done. In the midesophageal short-axis view, a bicuspid aortic valve was clearly identified (Fig 1A). In the 4- and 5-chamber views, a paracardiac mass also was found in the sulcus between the left atrial appendage and the left upper pulmonary vein. The mass was collapsed during cardiac systole because of high pressure during left atrial filling (Fig 1B and C). Persistent left superior vena cava (PLSVC) and enlarged coronary sinus were suspected. To confirm the diagnosis, a contrast medium of agitated saline was injected intravenously through the left and right antecubital veins, respectively. After agitated saline injection either in the left or right antecubital vein the contrast medium initially became visible in the coronary sinus and subsequently in the right cardiac chambers (Fig 1D-F and Video 1 [supplementary video accompanying this article is available online]). Computed venography was also performed and agreed with the TEE diagnosis.

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Fig 1. (A) A midesophageal short-axis view depicts bicuspid aortic valve. (B and C) Midesophageal 4- and 5-chamber views show enlarged coronary sinus (white arrow) in diastole and systole, respectively. (D and E) Agitated saline injection in the left antecubital vein depicts first the coronary sinus (gray arrow) and, subsequently, the right cardiac chambers (white arrow). No contrast is seen in the left cardiac chambers. (F) The saline is given into the right antecubital vein, and the contrast agent (double arrow) appears first in the dilated coronary sinus and thereafter in the right cardiac chambers (modified 4-chamber view). CS, coronary sinus; LV, left ventricle; RV, right ventricle.

PLSVC is the most frequent thoracic anomaly and commonly coexists with the right superior vena cava.3 In this case, echocardiographic examination and injection of contrast medium through the left antecubital vein immediately depicted the coronary sinus and then the right atria, whereas infusion into the right antecubital vein showed the right atria at first. In a different anatomic variation, PLSVC can be connected directly to the roof of the left atrial in a site between the left atrial appendage and the pulmonary veins. In that situation, injection of the contrast media either into the left or right antecubital vein depicts only the left and not the right cardiac chambers.3

In rare cases of right superior vena cava agenesis and PLSVC, the contrast first enters the dilated coronary sinus from both brachial veins and then drains into the right atria, as in our case.4 Although hemodynamics of patients with persistent left and agenesis of the right superior vena cava are not affected, oftentimes serious complications occur during central venous catheterization, cardiopulmonary bypass, and intracardiac electrode placement.5

In conclusion, physicians should always suspect the coexistence of other cardiac anomalies whenever a bicuspid aortic valve is diagnosed. This is the first case in which a bicuspid aortic valve is associated with an absent right and persistent left superior vena cava. In the setting of the intensive care unit, thorough contrast TEE examination can establish with accuracy the diagnosis of this anatomic variation and prevent serious complications during invasive procedures.