1. Answer: D. In patients with nonvalvular atrial fibrillation, low left atrial emptying velocities (<20 cm/s) have been associated with severe spontaneous echocardiographic contrast, appendage thrombus, and subsequent cardioembolic events. Data also suggest that patients with severe echo contrast have a poor prognosis with increased mortality.

2. Answer: B. TEE is a sensitive and highly specific technique for the diagnosis of aortic dissection. Intimal flaps are easily visualized when present in the proximal ascending aorta, distal arch, and descending thoracic aorta. Studies comparing TEE with computed tomography (CT) and magnetic resonance imaging (MRI) have shown that its sensitivity is >95%.

3. Answer: D. The non-coronary cusp is adjacent to the interatrial septum. The midesophageal TEE shortaxis view allows detailed visualization of the aortic valve anatomy. In normal trileaflet valves, the right coronary cusp is the most anterior cusp (farthest from the transducer).

4. Answer: C. Guidance of percutaneous interventions in structural heart disease is an expanding indication for TEE. Some of these procedures require a transseptal puncture (e.g., mitral valve procedures and left atrial appendage closure). Correct placement of the needle for transseptal puncture is paramount for the safety of the procedure. To avoid aortic puncture, the needle has to be manipulated posteriorly to the aorta. The best view for guidance in the anterior-posterior direction is the short-axis view at the level of the aortic root.

5. Answer: B. Some of the most feared complications of TEE occur during probe insertion. Knobs should never be locked to diminish the possibility of pharyngeal or esophageal injury. The probe should be inserted with the patient in the lateral decubitus position in moderately sedated patients and with anterior flexion of the neck. The probe should always be inspected before insertion, with an image on the screen confirming normal probe function. The new guidelines for Performing a Comprehensive Transesophageal Echocardiographic Examination have detailed descriptions of the appropriate techniques for probe insertion.

6. Answer: C. Although transthoracic echocardiography usually provides diagnostic imaging of the pathology of the tricuspid valve, TEE can offer additional information regarding anatomy and function. This is particularly relevant in patients with suspected endocarditis. It is then necessary to know the anatomy of the valve and the different TEE views to visualize its different components. The tricuspid leaflets are the anterior (with the longest radial length), septal (the shortest radial length), and the posterior. The tricuspid valve can be visualized in multiple views beginning with the midesophageal 4-chamber view. Because regurgitant jets are usually not coaxial with the ultrasound beam in this view, it is necessary to explore other angles. The 70-100-degree views are often the best for continuous wave Doppler interrogation. In patients with a normal-sized aorta, the 150-degree view is helpful for the visualization of tricuspid valve regurgitant jet size.

7. Answer: D. The evaluation of patients with aortic stenosis using TEE includes visualization of the aortic valve anatomy and planimetry of the aortic valve area. When possible, transvalvular gradients are obtained. However, obtaining accurate transaortic gradients can be technically challenging. It requires a deep transgastric view at 0 degrees with anteflexion of the probe tip. The objective is alignment of the aortic valve and proximal ascending aorta as parallel as possible with the continuous wave Doppler cursor. Alternatively, the transducer position can be set at 90-100 degrees and the probe slowly pulled back keeping the anteflexion and the tip adjusted with the lateral knob. These maneuvers are important not only in patients with valvular aortic stenosis but also in patients with hypertrophic obstructive cardiomyopathy.

8. Answer: B. In 2011, the new criteria for appropriateness for echocardiography were published (J Am Soc Echocardiogr. 2011;24:229-267). Of the options offered, answer (B) was considered an inappropriate indication for TEE. After pulmonary vein isolation, routine use of TEE in asymptomatic patients is not indicated. TEE is helpful in the guidance of noncoronary interventions and remains an important tool in the diagnosis of suspected aortic dissection. It is also indicated in patients with suboptimal TTE views when visualization of cardiac structures is essential for resolving diagnostic concerns.

9. Answer: C. In patients with atrial fibrillation, the presence of severe spontaneous contrast or smoke is a marker of increased risk of thromboembolic events. Electrical cardioversion causes left atrial appendage stunning with increased severity of echocontrast immediately after the procedure. There have been published series of cases of embolic stroke after cardioversion in patients with a negative TEE for left atrial thrombus who are not anticoagulated. For that reason, patients should have therapeutic levels of anticoagulation before proceeding with cardioversion. A recent series of patients with surgical LAA ligation showed a high incidence of residual flow between the left atrium (LA) and LAA.

10. Answer: C. TEE is highly sensitive for vegetations; however, other valvular structures should be considered in the differential diagnosis. For the aortic valve, these structures include Lambl’s excrescences, thickened Arantius nodules, and fibroelastomas. Lambl’s excrescences are filamentous structures attached to the ventricular side of the valve. Arantius nodules are present at the center of the free margin of each of the three cusps of the aortic valve. Fibroelastomas are benign tumors often attached to the aortic side of the valve.

11. Answer: C. TEE is a safe technique in the proper setting and in experienced hands. The overall incidence of complications is very low (0.18%-2.8%). The highest complication rates (>10%) are hoarseness and lip injury. Mortality is <0.02%.

12. Answer: B. TEE is an excellent technique to visualize the ascending aorta, distal arch, and the descending thoracic aorta. However, the distal ascending aorta and the proximal arch constitute a blind spot for TEE visualization. The blind spot is caused by the interposition of air, located in the trachea and main bronchi, between the transducer and the aorta.

13. Answer: C. Methemoglobinemia related to benzocaine topical anesthetic given during TEE is a rare reaction occurring in 0.07%-0.12% of patients. Methemoglobin levels are elevated due to conversion of iron from a reduced to oxidized form of hemoglobin which results in poor oxygen carrying capacity. This results in cyanosis, low oxygen saturation levels, and normal arterial Po₂ levels. Patients with methemoglobin levels >70% may develop circulatory collapse, neurologic depression, and death. The treatment of choice is intravenous methylene blue 1% solution (10 mg/mL) 1-2 mg/kg administered intravenously slowly for more than 5 minutes, followed by intravenous flush with normal saline.

14. Answer: C. Sometimes the TEE probe will become coiled in the esophagus with the tip pointed toward the mouth. Often, this can be remedied by withdrawing the probe to a slight extent, retroflexing the probe, and then attempting to advance the probe forward. However, it is always true that if simple maneuvers such as this do not work, then the TEE should not be continued and an endoscopy should be performed to rule out stricture or obstructing lesions.

15. Answer: D. Absolute contraindications to TEE include esophageal or pharyngeal obstruction, esophageal diverticulum, active gastrointestinal bleeding from an unknown source, and perforated viscus. Relative contraindications include esophageal varices, history of radiation to the neck, Barrett esophagus, and coagulopathy.

16. Answer: D. Degenerative mitral valve disease is the most common cause of severe mitral regurgitation requiring surgery. Echocardiography is the main diagnostic modality to assess mitral valve disease. Although TTE often offers enough diagnostic information, TEE is the gold standard for anatomical definition. Posterior mitral prolapse and/or flail are more common than anterior mitral pathology. A flail leaflet is diagnosed when ruptured chordae are visualized and the tip of the leaflet points superiorly into the left atrium in systole. In cases of posterior leaflet flail, the regurgitant jet is anteriorly directed.

17. Answer: C. Pulmonary vein flow assessment is part of a comprehensive evaluation in patients with mitral regurgitation. Figure 6-2 shows holosystolic flow reversal consistent with severe mitral regurgitation. In patients with mild mitral regurgitation, usually the pulmonary vein flow is normal with predominant or mildly blunted systolic flow. A large atrial reversal is seen in patients with increased end-diastolic pressure. In patients with mitral stenosis, the typical finding is a slow deceleration slope in the diastolic wave of the pulmonary vein flow.

18. Answer: D. Papillary fibroelastomas are benign tumors that can be seen on the aortic valve. These tumors are described as small, well-delineated, pedunculated masses with a predilection for valvular endocardium. These tumors can be highly mobile and carry an embolic risk. The diagnoses are usually incidental or during investigation for an embolic source. The echocardiographic characteristics of fibroelastomas are:

19. Answer: D. This is an example of an aortic dissection flap of the descending thoracic aorta with associated pleural effusion. Note the characteristic intimal flap that separates the true from the false lumen. The presence of a pleural effusion may represent a contained rupture but more often this represents an inflammatory pleural reaction. In patients with associated ascending aortic dissection with involvement of the aortic valve, pleural effusion may also indicate congestive heart failure.

20. Answer: D. This example shows two LAA thrombi. They are usually related to stagnant flow that can be seen in patients with atrial fibrillation or mitral valve disease, in particular stenotic lesions. These thrombi are more often seen at the tip of the appendage. Although usually they are single, they can be multilobulated. Differential diagnoses include prominent pectinate muscles and severe spontaneous echo contrast. Pectinate muscles are usually easy to identify using a multiplane TEE probe and can be seen as fingerlike structures at around 100-110-degree rotation. Severe spontaneous echo contrast (sludge) can be challenging to differentiate from a true clot. In some cases, the use of commercially available echo contrast agents may be helpful.

21. Answer: D. Myxomas are the most common benign tumors of the heart. They can be found in any of the heart cavities but most often in the left atrium. Typically, these tumors are attached by a stalk to the interatrial septum. Surgery is usually indicated due to the potential for embolism or obstruction of the mitral valve orifice. In most cases, these are single tumors; although in their familial form, they can be multiple and recurrent. Carney syndrome is an autosomal dominantly transmitted multisystem tumorous disorder characterized by myxomas (heart, skin, and breast), spotty skin pigmentation (lentigines and blue nevi), endocrine tumors (adrenal, testicular, thyroid, and pituitary), and peripheral nerve tumors (schwannomas). In Carney syndrome, the cardiac myxomas are also multiple and contribute to the mortality of this disease.

22. Answer: D. The proximal coronary arteries can be visualized using TEE. In patients with normal origin of the coronaries, the left main can be visualized as shown in the example. The right coronary artery can be more challenging due to its anterior origin and can be masked by aortic calcification.

23. Answer: D. This is an example of a unicuspid aortic valve. This is a relatively rare entity accounting for less than 5% of the adult population with aortic stenosis requiring surgery. Unicuspid valves can be unicommissural (most common) or acommissural.

24. Answer: A. Visualization of the pulmonary veins is important in a variety of situations: after pulmonary vein ablation, in patients with sinus venosus ASD, and in the assessment of mitral regurgitation. The easiest vein to visualize is the left upper pulmonary vein that runs next to the left atrial appendage. However, it is possible to visualize the bifurcation of the left and right pulmonary veins. The left pulmonary veins are typically seen from 110 to 140 degrees with counterclockwise rotation. In the example, the bifurcation can be easily seen with a transducer position at 110 degrees. Figure 6-18A corresponds to the left upper and lower pulmonary veins and Figure 6-18B corresponds to the right upper and lower pulmonary veins. The right pulmonary veins are usually visualized from 45- to 60-degree transducer position with clockwise rotation. (RLPV, right lower pulmonary vein; RUPV, right upper pulmonary vein.)