# Echocardiography in the Diagnosis and Management of Tricuspid Atresia
## 4 Echo-Doppler Features of TA on the Basis of Current Technology
In the example shown [31], the atretic tricuspid valve (Figures 13a and 14a), VSD (Figures 13b and 14b), hypoplastic RV (Figure 14a), single vessel (truncus) arising from the heart (Figures 13c,d, and 14c,d), and origin of the PA and its division into branch PAs (Figures 13d, and 14c,d) were demonstrated. Figure 7: Selected two dimensional, subcostal, four chamber echocardiographic frames with an open (**a**) and closed (**b**) atrioventricular valve. Line drawings on the right of (**a,b**) are made for greater clarity and for labeling. A large ostium primum atrial septal defect (\(1^{0}\) ASD) is shown in (**a**). When the large atrioventricular valve leaflet is open (**a**), it completely closes the right ventricle (RV) from the right atrium (RA) and the ventricular septal defect (VSD) and allows the emptying of blood from both atria into the left ventricle (LV). When the atrioventricular valve leaflet is closed, (**b**), it continues to occlude the RV from the RA while allowing the VSD to freely communicate between the RV and LV. Ap, Apex; AtTV, atretic tricuspid valve; Ba, base; L, left; LA, left atrium; R, right. Reproduced from [PERSON]. _[PERSON] Heart J_ 1987;58:409-412 [30]. Figure 8: Line drawings demonstrating two dimensional echocardiographic appearances in a sub-costal four chamber view of the muscular (**A**), membranous (**B**), and atrioventricular canal (**C**) variants of tricuspid atresia. (**A**) The atretic tricuspid valve is represented by a thick band of echoes between the right atrium (RA) and the small right ventricle (RV) in the muscular type. (**B**) The tricuspid valve is represented by a thin line in the membranous type. Note that crux of the heart (arrows in (**A**,**B**)) is clearly seen in both these types (**A**,**B**). The attachment of the anterior leaflet of the detectable atrioventricular value to the left side of the interatrial septum is evident. (**C**) In the atrioventricular canal type of tricuspid atresia, the anterior leaflet of the detectable atrioventricular canal is attached to the anterior wall of the heart, occluding the right ventricle from the right atrium, and allows the exit of blood from both atria into the left ventricle (LV). The crux cords and the atrioventricular portion of the interventricular septum are not seen. Reproduced from [PERSON]. _[PERSON]_ J 1987;58:409–412 [30] and from Reference [12]. Figure 9: Selected video frame from subcostal view of a patient with tricuspid atresia demonstrating right to left (R to L) shunt (arrow) across the interatrial communication. LA, left atrium; RA, right atrium. Reproduced from Reference [29]. Figure 11: (**A**) A selected video frame from parasternal long axis views of a patient with tricuspid atresia and transposition of the great arteries demonstrating the left atrium (LA), left ventricle (LV), a very small right ventricle (RV) and a moderate sized ventricular septal defect (not marked). The vessel coming off the LV is traced in (**B**) and shown to bifurcate into the left (LPA) and right (RPA) pulmonary arteries, confirming that this vessel is the main pulmonary artery (MPA), consistent with transposition of the great arteries. Ao, Aorta. Reproduced from Reference [29]. Figure 10: Selected video frames from parasternal long axis views of a patient with tricuspid atresia with normally related great arteries demonstrating an enlarged left atrium (LA) and left ventricle (LV), a small right ventricle (RV) and a moderate sized defect (VSD) (thick arrow) on 2D (**A**) and color flow (**B**) imaging. The turbulent flow (**B**), with a Doppler flow velocity of 2.91 m/s by continuous wave Doppler (**C**) across the VSD, suggests some restriction of the VSD. Ao, Aorta; PA, pulmonary artery. Reproduced from Reference [29].