This echocardiogram shows the markedly dilated right ventricle. The left atrium, interventricular septum, left ventricle and the mitral and aortic valves are well seen. In the real-time study that follows, note the markedly dilated right ventricle and the paradoxical motion of the interventricular septum. During systole, the septum moves anteriorly towards the right ventricle, rather than posteriorly, towards the left ventricle. as occurs normally. The left ventricle and the mitral and aortic valves are normal.
Secundum ASD
This is a diastolic still-frame of the sub-costal 4-chamber view that shows a dilated right ventricle and right atrium. The absence of echoes in the mid portion of the atrial septum is consistent with a secundum atrial septal defect The rea-time study follows.
Secundum color flow
This is a still-frame of a color flow Doppler from the same sub-costal view again showing the right atrium and left atrium. The red color indicates blood flowing anteriorly towards the transducer. This flow crosses de mid portion of the atrial septum from the left atrium into the right atrium. In the real-time study that follows, the left-to-right shunt is well seen.
TEE animation
In some patients, particularly adults, transesophageal echocardiography can best show the anatomy of the atrial septum. The presence, location and size of the defect can be determined with confidence. In this illustration, the transesophageal probe is being inserted into the esophagus. The tip containing the echo transducer will be advanced to positions behind the heart, where echo images will be obtained in several planes.
4-chamber TEE
This is a systolic still-frame of a 4-chamber transesophageal echocardiogram. The right ventricle and right atrium are dilated. Portions of the left atrium and left ventricle are shown and appear to be normal in size. There is absence of echos in the mid portion of the atrial septum, diagnostic of a secundum atrial septal defect. In the real-time study that follows, note that the tricuspid and mitral valves move normally.
TEE bubble study
This is a transesophageal still-frame from another patient with an atrial septal defect obtained during a so-called bubble study. After saline is shaken, or agitated, to cause bubbles to form, it is injected into a peripheral arm vein. The bubbles, along with the "negative jet" are seen in the right atrium. The "negative jet" is created by blood streaming through the attrial septal defect from the left atrium into the right atrium and displacing the agitated saline. The real-time study follows.
PFO colorized TEE bubble study
A bubble study may also be used to define the presence of a patent foramen ovale (PFO). This is a still-frame of a colorized transesophageal echocardiogram at the level of the atria from another patient with a patent foramen. The triangle encompasses part of the right atrium, interatrial septum and left atrium. A patent foramen ovale is present in approximately 15% of normal adults. The volume of flow is small and the direction is left-to-right. With coughing or straining, hoever, a transient right-to-left shunt can occur, as seen in this echo. This is a risk factor for an embolic stroke, as in some patients an embolus can cross from right-to-left through a patent foramen ovale. In the real-time study that follows, "microbubbles" are seen to cross into the left atrium.