1. Correct Answer: C. Peak velocity of >4.0 m/s

Rationale: The cutoff for severe AS graded by peak velocity measurement is >4.0 m/s.

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 Echocardiogr. 2017;30:372-392.

2. Correct Answer: B. RV-focused apical four-chamber view with basal linear dimension measured at the basal one-third of the RV inflow at end systole

Rationale: The RV basal linear dimension should be measured in the basal one-third of the RV inflow at end diastole in the RV-focused apical four-chamber view.

1. Lang RM, Badano LP, Mor-Avi V, et al. Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr. 2015;28(1):1-39.e14.

2. Rudski LG, Lai WW, Afilalo J, et al. Guidelines for the echocardiographic assessment of the right heart in adults: a report from the American Society of Echocardiography endorsed by the European Association of Echocardiography, a registered branch of the European Society of Cardiology, and the Canadian Society of Echocardiography. J Am Soc Echocardiogr. 2010;23(7):685-713; quiz 786-788. doi:10.1016/j.echo.2010.05.010. PMID: 20620859.

3. Correct Answer: D. RV mid-diameter of 48 mm

Rationale: The normal wall thickness of the RV is 0.5 cm or less; greater than 0.5 cm is considered RV hypertrophy. The normal range of dimensions of the RV are as follows: RV basal diameter of 25 to 41 mm, RV mid-diameter of 19 to 35 mm, and RV longitudinal diameter of 59 to 83 mm. TR jet velocity may indicate elevated right ventricular systolic pressure (RVSP) but does not provide any information about the size of the right ventricle.

1. Lang RM, Badano LP, Mor-Avi V, et al. Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr. 2015;28(1):1-39.e14.

4. Correct Answer: B. RV FAC of less than 35%

Rationale: An RV FAC of <35% reflects abnormal RV systolic function.

1. Lang RM, Badano LP, Mor-Avi V, et al. Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging. J Am Soc Echocardiogr. 2015 Jan;28(1):1-39.e14.

2. Rudski LG, Lai WW, Afilalo J, et al. Guidelines for the echocardiographic assessment of the right heart in adults: a report from the American Society of Echocardiography. J Am Soc Echocardiogr. 2010;23:685-713.

5. Correct Answer: A. TAPSE is a measurement of the circumferential systolic performance of the right ventricle

Rationale: TAPSE is a measurement of the longitudinal systolic performance of the right ventricle. It’s advantages include its simplicity of measurement even in the setting of poor image quality, reproducibility, and the fact that it does not require complex echocardiography equipment or image analysis. TAPSE below 1.6 cm is considered abnormal. TAPSE incorrectly assumes that the displacement of a single segment represents the function of a complex 3D right ventricle. Additionally, TAPSE is angle dependent and may be load dependent.

1. Rudski LG, Lai WW, Afilalo J, et al. Guidelines for the echocardiographic assessment of the right heart in adults: a report from the American Society of Echocardiography. J Am Soc Echocardiogr. 2010;23:685-713.

6. Correct Answer: B. Improved contractility

Rationale: Improved contractility. This series of images demonstrate the concept of low-flow low-gradient AS. In Figure 40.2A, the 2D appearance of the AV is hyperechoic and heavily calcified, raising suspicion for a stenotic lesion and we are told that at this time the LVOT VTI was 12 cm, indicating that the patient is in a state of low cardiac output. In Figure 40.2B, the spectral Doppler tracing demonstrates a mean pressure gradient of 28 mm Hg and a maximum velocity of 3.3 m/s, which do not meet the criteria for severe AS. We are then told that the patient recovered from his illness, and in Figure 40.2C the spectral Doppler demonstrates an LVOT VTI of 22.8 cm, which is greatly improved from 12 cm and confirms that the heart is indeed ejecting an improved stroke volume. In Figure 40.2C we can also see that his AV measurements now meet the cutoff for severe AS:pressure gradient (PG) mean of 41.7 and Vmax of 4.2 m/s. This phenomenon is termed “low-flow low-gradient AS.” Essentially, when cardiac output is low, the heart is unable to generate a high enough velocity to reach the cutoff for severe AS despite the low-valve area. Once the heart has recovered contractility, the measurements reflect the true severity of AS. In states where the cardiac output is low, the severity of AS cannot be assumed by gradients alone. One viable metric is the dimensionless index, or the ratio of the LVOT VTI to the AV VTI. A value of less than 0.25 is consistent with severe AS. Another method for revealing true AS in the setting of low cardiac output is a dobutamine stress echo.

1. Clavel MA, Burwash IG, Pibarot P. Cardiac imaging for assessing low-gradient severe aortic stenosis. JACC Cardiovasc Imaging. 2017;10(2):185-202.

7. Correct Answer: D. All of the above are seen with cardiac tamponade physiology

Rationale: When fluid accumulates in the pericardial sac, the pressure in the pericardial sac rises and tamponade physiology develops when this excessive pericardial pressure limits cardiac filling. With elevated pericardial pressures, systemic (superior vena cava [SVC] and IVC) and pulmonary venous pressures must also rise to maintain cardiac filling. As tamponade physiology develops, the gradients between the veins and the cardiac chambers diminish, resulting in less filling and lower cardiac output. The limitation of chamber filling on cardiac output is based not only on the amount of pericardial fluid, but on the pressure within the pericardial sac. This is variable among patients and because of this, cardiac tamponade is a clinical, not echocardiographic diagnosis. However, these echo findings reflect the equalization of cardiac diastolic and pericardial pressures.

1. Klein AL, Abbara S, Agler DA, et al. American Society of Echocardiography clinical recommendations for multimodality cardiovascular imaging of patients with pericardial disease, endorsed by the Society for Cardiovascular Magnetic Resonance and Society of Cardiovascular Computed Tomography. J Am Soc Echocardiogr. 2013; 26:965-1012.

8. Correct Answer: B. Cardiac tamponade

Rationale: When tamponade is suspected, 2D echocardiography should be obtained emergently. Regardless of the effusion size, cardiac tamponade can be lethal. The symptoms and signs of tamponade depend on the etiology of the effusion and the rate of fluid accumulation within a relatively fixed pericardial space and can range from mild to severe and life threatening. Mild tamponade is usually asymptomatic, whereas when the pressure in the pericardium rises above about 15 mm Hg, symptoms including dyspnea, tachycardia, and hypotension develop due to decreasing cardiac output. Invasive cardiac procedures that can result in bleeding into the pericardium acutely can cause tamponade with as little volume as 250 mL. First line approach to treatment is removal of the effusion by echo-guided pericardiocentesis, which has been found to be relatively safe. Although imaging contributes significantly to the differential, tamponade is always a clinical diagnosis.

1. Klein AL, Abbara S, Agler DA, et al. American Society of Echocardiography clinical recommendations for multimodality cardiovascular imaging of patients with pericardial disease, endorsed by the Society for Cardiovascular Magnetic Resonance and Society of Cardiovascular Computed Tomography. J Am Soc Echocardiogr. 2013; 26:965-1012.

9. Correct Answer: D. A distended right ventricle with depressed free wall motion

Rationale: As tamponade physiology progresses, the gradients for venous filling of the cardiac chambers are decreased and as a result the chambers are underfilled and decompressed. To compensate, venous pressures are increased, which is seen by fixed and enlarged IVC. The cyclical changes in left and right heart filling pressures with the respiratory cycle create the variation in transmitral filling patterns. Notably, the majority of pericardial effusions do not lead to tamponade physiology.

1. Nagdev A, Stone MB. Point of care ultrasound evaluation of pericardial effusions: does this patient have cardiac tamponade? Resuscitation. 2011;82:671-673.

10. Correct Answer: A. Decreased mitral transvalvular velocity with inspiration

Rationale: The spectral Doppler displays a decreasing velocity with inspiration, a state that is characteristic of the transmitral filling pattern in a spontaneously breathing tamponade patient. In a normal state, inspiration leads to reduction in intrathoracic pressures, which create increased venous return to the right heart and a simultaneous decrease in filling of the left heart. With expiration, there is an increase in left heart filling and a decrease in right heart filling; therefore, the transmitral and transtricuspid flow have opposite respiratory variation. As ventricular interdependence develops in a tamponade state, the changes in mitral inflow velocity are much larger. A 25% inspiratory reduction in mitral peak E-wave velocity is considered diagnostic of tamponade physiology.

1. Leeman DE, Levine MJ, Come PC. Doppler echocardiography in cardiac tamponade: exaggerated respiratory variation in transvalvular blood flow velocity integrals. J Am Coll Cardiol. 1988;11:572-578.

11. Correct Answer: B. Absence of cardiac chamber collapse

Rationale: The absence of any cardiac chamber collapse has a >90% negative predictive value for clinical cardiac tamponade. Multiple physiologic states can cause fixed and dilated IVC, as well as changes in the transmitral flow patterns. A large amount of fluid can be present in the pericardium without tamponade physiology.

1. Merce J, Sagrista-Sauleda J, Permanyer-Miralda G, Evangelista A, Soler J. Correlation between clinical and Doppler echocardiographic findings in patients with moderate and large pericardial effusion: implications for the diagnosis of cardiac tamponade. Am Heart J. 1999;138:759-764.

12. Correct Answer: A. Barcode sign; pneumothorax

Rationale: The appearance of a “barcode sign” is the characteristic M-mode finding when there is no movement of the underlying lung tissue. Since M-mode measures the motion along one scan line over time, the appearance of straight, constant lines denotes that the structure is fixed and not moving. In contrast, when M-mode is applied to the lung during normal respiration, there are no fixed straight lines and instead there is a disjointed speckled appearance that is the M-mode equivalent of lung sliding seen on 2D ultrasound. “Barcode sign” is present in states other than pneumothorax in which the lung is not moving, including apnea, trapped lung, and prior pleurodesis.

1. Husain LF, Hagopian L, Wayman D, Baker WE, Carmody KA. Sonographic diagnosis of pneumothorax. J Emerg Trauma Shock. 2012:5(1):76-81.

13. Correct Answer: D. A and C

Rationale/Critique: Lung ultrasound is more sensitive and specific than CXR in the detection of pneumothorax.

1. Lichtenstein DA, Menu Y. A bedside ultrasound sign ruling out pneumothorax in the critically ill. Chest. 1995;108:1345-1348.

14. Correct Answer: C. TR jet > 2.8 m/s

Rationale/Critique: Figure 40.6 is a short-axis view of the left ventricle showing septal flattening and an enlarged right ventricle, indicating a state of acute RV pressure and/or volume overload. In this setting, typically RV function is reduced, the IVC is dilated, TR is elevated, and the left-sided atrial and ventricular pressures are low.

1. Kurnicka K, Lichodziejewska B, Goliszek S, et al. Echocardiographic pattern of acute pulmonary embolism: analysis of 511 consecutive patients. J Am Soc Echocardiogr. 2016;29:907-913.

15. Correct Answer: D. Improper probe placement can make the RV appear falsely small

Rationale: The normal RV:LV ratio is 0.6:1, with the right ventricle normally appearing smaller than the left ventricle. It is possible that the RV can dilate and still maintain its functional measures, including normal FAC, ejection fraction (EF), and TAPSE. The RV will dilate in response to pressure and/or volume overload. Improper probe placement can lead to nonstandard views and inaccurate assessment of RV size.

1. Rudski LG, Lai WW, Afilalo J, et al. Guidelines for the echocardiographic assessment of the right heart in adults. J Am Soc Echocardiogr. 2010;23:685-713.

16. Correct Answer: A. AV jet velocity > 3.5 m/s

Rationale: The cutoffs for quantifying severe AS are as follows: AV jet velocity of > 4.0 m/s, mean gradient > 40 mm Hg, AV area continuity < 1.0 cm², or LVOT/AV velocity ratio < 0.25.

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 Echocardiogr. 2017;30:372-392.

17. Correct Answer: C. pulmonary embolism

Rationale: A dilated right ventricle with severe hypokinesis or akinesis of the free wall and relative hyperkinesis of the apex is characteristic for a large pulmonary embolism and is known as McConnell’s sign. The left ventricle would most likely be underfilled and hyperdynamic. It is important to note that McConnell’s sign is not specific for PE and can also be seen with other pathologies, including right coronary artery (RCA) infarctions.

1. Kurnicka K, Lichodziejewska B, Goliszek S, et al. Echocardiographic pattern of acute pulmonary embolism: analysis of 511 consecutive patients. J Am Soc Echocardiogr. 2016;29:907-913.

18. Correct Answer: B. Give a bolus of lactated Ringer’s solution

Rationale: This patient is experiencing systolic anterior motion (SAM) of the mitral valve that is causing obstruction of the LVOT as well as mitral regurgitation due to the displaced leaflet, creating the characteristic Y-shaped pattern as seen on color flow Doppler (Figure 40.7). The best steps in immediate management are to administer adequate fluid resuscitation and to decrease or discontinue any inotropes.

1. Alfieri O, Lapenna E. Systolic anterior motion after mitral valve repair. Eur J Cardiothorac Surg. 2015;48:344-346.

19. Correct Answer: A. Increase in transtricuspid velocities and decrease in transmitral velocities

Rationale: During the respiratory cycle in a normal heart, transthoracic pressures are transmitted relatively constantly to the vasculature as well as to the chambers of the heart, such that the pressure gradient between the pulmonary veins and the left atrium and ventricle has minimal variation. This is reflected in transmitral velocities that usually have <5% variation. In constrictive pericarditis, a noncompliant pericardium leads to relative isolation of intracardiac pressures from intrathoracic pressures and thus a decrease in the gradient between the pulmonary veins and the left heart during inspiration. Because the noncompliant pericardium also causes increased ventricular interdependence, this decrease in left-sided filling is accompanied by an increase in right-sided filling and thus the expected velocities as noted in answer choice A. The opposite occurs during expiration.