PMC10352079_01
Two-dimensional and color Doppler echocardiogram images of the origin (A,B) and termination (C,D) of the aorta-right atrial tunnel. The tunnel originated from the right coronary sinus of Valsalva in the ventral direction and then ran rightward on the parasternal short-axis view (A,B). The tunnel running adjacent to the right ventricular and right atrial free wall was terminated in the right atrium from the modified right parasternal long-axis view (C,D). Ao, aorta; LV, left ventricle; MPA, main pulmonary artery; RA, right atrium; RV, right ventricle; TV, tricuspid valve.
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fig1
The tunnel originated from the right coronary sinus of Valsalva extending in a ventral direction and the diameter of the origin orifice was measured to be about 6 mm from the right parasternal short-axis (level of aortic root) view (Figures 1A,B). The termination orifice diameter was approximately 2.3 mm, much smaller than the origin orifice diameter (Figures 1C,D). Color Doppler echocardiography demonstrated blood flow from the aorta to the RA (Figures 1B,D), and continuous-wave Doppler profile obtained across the shunt site showed a continuous wave with systolic and diastolic pattern with a pressure gradient of 7.8 mm Hg.
Two-dimensional and color Doppler echocardiogram images of concurrent findings. Blood flow from the vessel (dotted arrow) within the interventricular septum to the right ventricle was confirmed from a modified right parasternal long-axis view (A,B). From the right parasternal short-axis view, blood flow (solid arrow) from the proximal aorta-right atrial tunnel runs between the aorta and the right atrium (C), and the mosaic pattern between the aorta and the main pulmonary artery (D) were identified. Ao, aorta; LA, left atrium; LV, left ventricle; MPA, main pulmonary artery; RA, right atrium; RV, right ventricle.
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In addition, a small communication between the blood vessel within the interventricular septum and the RV was confirmed (Figures 2A,B). Moreover, another blood flow arising from the proximal aorta-RA tunnel was also identified, and it runs between the aorta and the RA from the right parasternal short-axis (level of the aortic root) view, which was considered the dilated RCA branch (Figure 2C). On the same view, since the mosaic pattern was observed between the ascending aorta and the main pulmonary artery, the aortopulmonary window and a supracristal ventricular septal defect were included in the differential diagnoses (Figure 2D).
Computed tomography images of the aorta-right atrial tunnel. The tunnel originating from the right coronary sinus of Valsalva extending in a ventral ventral direction runs rightward (A), caudodorsal to the aortic root (B). After a tortuous course adjacent to the right ventricular and right atrial free wall (C), the tunnel entered the right atrium (D). Ao, aorta; LVOT, left ventricular outflow tract; MPA, main pulmonary artery; RA, right atrium.
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CT images revealed a tunnel originating from the right coronary sinus of Valsalva extending in a ventral direction, running rightward, caudal to the aortic root along the RV and RA-free wall, and terminating in the RA (Figure 3).
Illustration of the aorta-right atrial tunnel made with reference to the three-dimensional computed tomographic reconstruction. The origin orifice can be observed on the cross-section of the heart at the aortic valve level. The tunnel's origin from the right coronary sinus of Valsalva and entry to the right atrium through a tortuous communication was confirmed. LA, left atrium; LC, left coronary cusp; MPA, main pulmonary artery; NC, non-coronary cusp; RA, right atrium; RC, right coronary cusp; RV, right ventricle.
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An illustration made with reference to the three-dimensional CT reconstruction helped delineate the morphologic structure of the aorta-RA tunnel (Figure 4).