1. Correct Answer: D. Parasternal long-axis view for the ascending aorta and suprasternal views for the aortic arch

Rationale: Evaluation of the proximal ascending aorta and aortic arch using TTE is performed primarily in two views. In the parasternal long-axis view, the aortic valve, aortic root, and ascending aorta are visualized in long axis and the descending aorta is seen in short axis. Whereas the aortic arch is often a “blind spot” in TEE, the suprasternal view in TTE allows visualization of the distal ascending aorta, aortic arch, three great vessels (innominate, left carotid, and left subclavian arteries), as well as the proximal descending aorta. In addition to measurements for hemodynamic calculations and evaluation of aortic valve pathologies, aortic aneurysm, and aortic dissection, these views are also useful for evaluation of aorta atheroma and positioning of intra-aortic balloon pumps.

1. Evangelista A, Flachskampf FA, Erbel R, et al. Echocardiography in aortic diseases: EAE recommendations for clinical practice. Eur J Echocardiogr. 2010;11:645-658.

2. Correct Answer: B. Systole, parasternal long-axis view

Rationale: Measurement of the LVOT should occur during midsystole (valve leaflets open) in the parasternal long-axis view. The image should be zoomed as closely as possible to minimize error and measurements should be made parallel to the aortic valve annulus and at the level of the annulus. Error in the LVOT diameter will be exaggerated in calculations of valve area using the continuity equation, with an undermeasured LVOT diameter leading to an underestimated aortic valve area. The dimensionless index can be used as an alternative valve area calculation to avoid this error.

1. Baumgartner H, Hung J, Bermejo J, et al. Recommendations on the echocardiographic assessment of aortic valve stenosis: a focused update from the European Association of Cardiovascular imaging and the American Society of Echocardiography. J Am Soc Echocardiogra. 2017;30:372-392.

3. Correct Answer: C. Akinesis of the RV free wall with apical sparing

Rationale: Acute PE may present with RV dysfunction due to pressure overload from high pulmonary vascular resistance and obstructed PA flow. While CT angiography has become the gold standard for evaluation of PE, echocardiography is a useful adjunct for diagnosis and management. Both the McConnell sign, RV free wall motion abnormality with sparing of the apical segment, and the 60-60 sign, an RV systolic pressure <60 mm Hg and a pulmonary acceleration time <60 msec, have been found to have high specificity (100% and 94%, respectively) and high positive predictive values (100% and 90%, respectively) for RV dysfunction in the setting of PE. Mobile intracardiac thrombus and depressed tricuspid annular plane systolic excursion (TAPSE) may further support a diagnosis of RV pressure overload, and at least 25% of patients with PE will demonstrate RV dilatation.

1. Konstantinides SV, Torbicki A, Agnelli G, et al. 2014 ESC Guidelines on the diagnosis and management of acute pulmonary embolism. Eur Heart J. 2014;35:3033-3080.

2. Kurzyna M, Torbicki A, Pruszczyk P, et al. Disturbed right ventricular ejection pattern as a new Doppler echocardiographic sign of acute pulmonary embolism. Am J Cardiol. 2002;90:507-511.

4. Correct Answer: D. Aortic leaflet perforation

Rationale: AR occurs in approximately 50% to 70% of patients with Type A aortic dissections. The severity of AR is usually explained by pathologic changes in the valve and annular structure because of the dissection in patients with anatomically normal valves. Mechanisms of AR include dilatation of the aortic root leading to incomplete aortic leaflet coaptation, aortic cusp prolapse from an asymmetric dissection depressing one or more cusps below the annulus, disruption of the aortic annular support resulting in a flail leaflet, as well as invagination or prolapse of a dissection flap through the aortic valve in diastole. Determining the mechanism and severity of AR is important for surgical decision-making in determining whether to replace the aortic valve as part of the dissection repair.

Aortic leaflet perforation more commonly results from structural deterioration of the valve, usually from aortic valve endocarditis, making it the least likely choice.

1. Goldstein S, Evangelista A, Abbara S, et al. Multimodality imaging of diseases of the thoracic aorta in adults: from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr. 2015;28:119-182.

2. Keane MG, Wiegers S, Yang E, Ferrari VA, St John Sutton MG, Bavaria JE. Structural determinants of aortic regurgitation in type A dissection and the role of valvular resuspension as determined by intraoperative transesophageal echocardiography. Am J Cardiol. 2000;85(5):604-610.

5. Correct Answer: A. Aortic dissection

Rationale: Diastolic fluttering of the anterior leaflet of the mitral valve may be caused by a regurgitant aortic valve jet directed toward the mitral valve. Fluttering may be noted on direct visualization using echocardiography or by using M-mode Doppler through the mitral valve leaflets. Acute aortic dissection with a retrograde dissection flap or involvement of the aortic valve annulus is likely to cause AI. In this patient, with acute chest pain and multiple risk factors for aortic dissection, the most likely mechanism for diastolic fluttering of the mitral valve is AI related to acute aortic dissection. Despite the presence of an aortic aneurysm (choice B), the absence of annular dilatation makes AI unlikely, particularly with the acute onset of symptoms described in the question. Inferior and lateral wall myocardial infarctions are unlikely to lead to AI. Other causes of diastolic fluttering include atrial fibrillation, which is characteristically of lower frequency than that associated with AI.

1. Louie EK, Mason TJ, Shah R, Bieniarz T, Moore AM. Determinants of anterior mitral leaflet fluttering in pure aortic regurgitation from pulsed Doppler study of the early diastolic interaction between the regurgitant jet and mitral inflow. Am J Cardiol. 1988;61:1085-1091.

2. Winsberg F, Gabor GE, Hernberg JG, Weiss B. Fluttering of the mitral valve in aortic insufficiency. Circulation. 1970;41:225-229.

6. Correct Answer: B. Line B

Rationale: Measurement of the aortic root diameter should be made perpendicular to the axis of the proximal aorta. The American Society of Echocardiography recommends measurements be performed from leading edge to leading edge, at end-diastole, and perpendicular to the long axis of the aorta, as demonstrated in Figure 32.1 (Line B). End-diastolic measurements have great reproducibility as the aortic pressure is most stable during late diastole. Other techniques for measuring the aorta include the inner edge-to-inner edge approach, although this has not shown to reproduce measurements most similar to CT and MRI compared to the leading edge-to-leading edge approach.

1. Goldstein S, Evangelista A, Abbara S, et al. Multimodality imaging of diseases of the thoracic aorta in adults: from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr. 2015;28:119-182.

7. Correct Answer: D. Right pulmonary artery (PA)

Rationale: In Figure 32.2, the parasternal short-axis view of the great vessels is obtained in the left parasternal window by rotating 90° from the parasternal long-axis view and then tilting the ultrasound probe beam superiorly. A portion of the aortic valve and the ascending aorta is seen in cross section as well as the right atrium, RV outflow tract, pulmonary valve, and the main PA with the left and right PA branches in this view. The main PA diameter can be measured in this view midway between the pulmonic valve and the PA bifurcation, using an inner edge-to-inner edge technique at end-diastole. (See Figure 32.9.)

1. Mitchell C, Rahko P, Blauwet L, et al. Guidelines for performing a comprehensive transthoracic echocardiographic examination in adults; recommendations from the American Society of Echocardiography. J Am Soc Echocardiogr. 2019;31(1):1-64.

2. The comprehensive echocardiographic examination. In: Armstrong WF, Ryan T, eds. Feigenbaum’s Echocardiography. 8th ed. Wolters Kluwer; 2019:61-99.

8. Correct Answer: C. Pulmonary hypertension

Rationale: TTE is used to image the effects of pulmonary hypertension on the heart and estimate the systolic PA pressure using Doppler measurements. Echocardiographic signs suggestive of pulmonary hypertension include RV dilatation, RV hypertrophy, flattening of the intraventricular septum, enlarged right atrium, and an enlarged PA. The PA dimension is measured in end-diastole halfway between the pulmonic valve and the bifurcation of the main PA. A diameter >25 mm is considered abnormal. As the PA dilates in response to chronic volume and pressure overload, an acute PE is unlikely to lead to a finding of an enlarged PA. Pulmonary edema would not result in PA dilatation. While a peak tricuspid regurgitant velocity of 3.5 m/s would be indicative of diastolic dysfunction, this finding suggests left atrial pressure overload in the presence of normal PAs and would thus indicate more severe forms of diastolic dysfunction (Grade 2 or 3).

1. Augustine D, Coates-Bradshaw L, Willis J, et al. Echocardiographic assessment of pulmonary hypertension: a guideline protocol from the British Society of Echocardiography. Echo Res Pract. 2018;5(3) G11-G24.

2. Galie N, Humbert M, Vachiery, J, et al. 2015 ESC/ERS guidelines for the diagnosis and treatment of pulmonary hypertension: The Joint Task Force for the Diagnosis and Treatment of Pulmonary Hypertension of the European Society of Cardiology (ESC) and the European Respiratory Society. Eur Heart J. 2016;37(1):67-119.

9. Correct Answer: D. Bicuspid aortic valve

Rationale: Coarctation of the aorta refers to a discrete narrowing, or stricture, of a portion of the aorta, usually found distal to the left subclavian artery. Clinical presentation of coarctation depends on the location and severity of the stricture. Over time, aortic coarctation can cause reduced blood flow to the lower body, which may present as severe hypertension. A bicuspid aortic valve is present in over 50% of patients with aortic coarctation while <10% of patients with a bicuspid aortic valve have coarctation. While imaging of the coarctation is possible by TTE, CT and MRI aortography are best to determine the exact site, degree of obstruction, and the extent of collaterals which develop over time due to the restricted flow.

1. Goldstein S, Evangelista A, Abbara S, et al. Multimodality imaging of diseases of the thoracic aorta in adults: from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr. 2015;28:119-182.

10. Correct Answer: B. Aortic isthmus just distal to the left subclavian artery

Rationale: The aortic isthmus is the most common location for BAIs, accounting for 80% to 95% of aortic injuries from blunt force trauma. The next most common locations of BAIs are the supravalvular portion of the ascending aorta and the diaphragmatic portion of the descending thoracic aorta. These regions represent transition points between relatively fixed and mobile points of the aorta and have the greatest exposure to shear and hydrostatic forces during abrupt deceleration. TTE has a limited role in the assessment of aortic injury following blunt chest trauma, largely due to suboptimal echocardiographic findings. TTE may be helpful to assess for myocardial contusions and valvular pathology. TEE allows acquisition of additional data that may evaluate areas of the aorta not accessible by TTE if clinical suspicion is high and CT imaging is not feasible in unstable patients who need emergent operating room (OR) exploration.

1. Goldstein S, Evangelista A, Abbara S, et al. Multimodality imaging of diseases of the thoracic aorta in adults: from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr. 2015;28:119-182.

2. Karalis DG, Victor MF, Davis GA, et al. The role of echocardiography in blunt chest trauma: a transthoracic and transesophageal echocardiographic study. J Trauma. 1994;36:53-58.

11. Correct Answer: B. Immediate surgical consultation and initiation of anti-impulse therapy

Rationale: The bedside echocardiography findings are suggestive of a Type A (or DeBakey I/II) aortic dissection. The finding of a mobile intimal flap prolapsing into the left ventricle in addition to aortic root dilatation and AI is highly specific for aortic dissection. Other findings that may be visualized on TTE in patients with aortic dissection include flail aortic leaflets, wall motion abnormalities, pericardial effusion or tamponade, and differential color Doppler flow patterns within the true and false lumens. While TTE has limited diagnostic value for the initial diagnosis of aortic dissection, it is safe, portable, inexpensive, quick, and highly specific. Additionally, TTE is valuable for diagnosing the complications of aortic dissection including AR and pericardial effusions.

1. Solomon SD. Essential Echocardiography: A Practical Handbook. Humana Press Inc.; 2007.

12. Correct Answer: D. All of the above

Rationale: All of the above are factors predisposing to aortic dissection. Cystic medial degeneration (e.g., Marfan syndrome and Ehlers-Danlos syndrome) account for 5% to 9% of all aortic dissection cases. Marfan syndrome is responsible for the majority of aortic dissection in patients under the age of 40 years. Turner syndrome, Noonan syndrome, and coarctation of the aorta have also been associated with a higher risk of dissection. Other known risk factors for aortic dissection include polycystic kidney disease, bicuspid aortic valvular disease, Takayasu disease, Loeys-Dietz syndrome, and giant cell arteritis.

1. Goldstein S, Evangelista A, Abbara S, et al. Multimodality imaging of diseases of the thoracic aorta in adults: from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr. 2015;28:119-182.

2. Solomon SD. Essential Echocardiography: A Practical Handbook. Humana Press Inc.; 2007.