1. Correct Answer: A. Endocarditis

Rationale: Figure 28.1 shows a mass on the anterior leaflet of the mitral valve consistent with a vegetation from endocarditis. Episodes of endocarditis have been increasing in recent years and there are now up to 50,000 cases per year diagnosed in the United States. Echocardiography is key to making the diagnosis of endocarditis. TTE has been reported to have overall ˜70% sensitivity, with TEE being even more sensitive and specific. Echocardiographic signs of endocarditis include valvular vegetations, paravalvular abscesses, and intracardiac fistulae. In a patient with bacteremia or sepsis with unknown source, the possibility of endocarditis should be evaluated. The TTE image shown in Figure 28.1 reveals no evidence of a ventricular septal defect or an LV pseudoaneurysm. Hypovolemia is a clinical diagnosis that can be informed by echocardiographic information. This image shows no findings suggestive of hypovolemia.

1. Afonso L, Kottam A, Reddy V, Penumetcha A. Echocardiography in infective endocarditis: state of the art. Curr Cardiol Rep. 2017;19(12):127.

2. Correct Answer: B. Mechanical aortic valve stenosis

Rationale/Critique: Figure 28.2 shows CWD measurements through the aortic valve. Normal mean pressure gradients through a properly functioning aortic valve are <10 mm Hg. The values in this patient are significantly elevated, with a mean pressure gradient of 48.51 mm Hg. These values are most consistent with stenosis of his mechanical aortic valve. The exact cause of the stenosis cannot be determined from CWD measurement alone. In general, mechanical valves have a longer potential life span than bioprosthetic valves, but both types of valves can malfunction over time. Severe aortic stenosis can result in congestive heart failure and pulmonary edema and may have played a role in the patient’s development of pneumonia. Regurgitation of the mechanical valve and a paravalvular leak both would show flow of blood backward into the left ventricle, which are not present in Figure 28.2.

1. Chikwe J, Filsoufi F, Carpentier AF. Prosthetic valve selection for middle-aged patients with aortic stenosis. Nat Rev Cardiol. 2010;7(12):711-719.

3. Correct Answer: C. Mechanical mitral valve thrombosis

Rationale: Figure 28.3 shows a mass on the patient’s mechanical mitral valve that is consistent with mechanical mitral valve thrombosis. The risk of thrombosis is approximately five times greater for prosthetic valves in the mitral position than in the aortic position. Patients with valve thrombosis may be asymptomatic with small, slowly developing thrombus, or acutely symptomatic with signs of reduced cardiac output when a large thrombus develops quickly. Echocardiographic signs of valve thrombus include an abnormal mass on the prosthetic valve, restricted valve motion, and elevated flow gradients through the valve. Management of mechanical valve thrombosis ranges from directed thrombolysis to open surgical repair.

1. Lim WY, Lloyd G, Bhattacharyya S. Mechanical and surgical bioprosthetic valve thrombosis. Heart. 2017;103(24):1934-1941.

4. Correct Answer: D. Paravalvular leak

Rationale: The TEE image (Figure 28.4) shows a paravalvular leak around the TAVR valve. This can be seen in the long-axis view of the transcatheter valve as regurgitant flow around the posterior edge of the valve back into the LV outflow tract, and in the short-axis view of the valve as color flow during diastole at approximately 2 o’clock. Echocardiographic assessment for paravalvular leak is important after all TAVR procedures because its presence is associated with poorer long-term outcomes. Stenosis of the transcatheter aortic valve would be best evaluated with CWD measurements through the valve and is not indicated by the regurgitant flow in the images. Signs of endocarditis such as vegetations and abscesses are not present in the images and endocarditis of the valve would be essentially impossible immediately after the procedure. Finally, the valve appears to be appropriately positioned.

1. Vollema EM, Delgado V, Bax JJ. Echocardiography in transcatheter aortic valve replacement. Heart Lung Circ. 2019;28(9):1384-1399.

5. Correct Answer: A. Cardiac tamponade

Rationale: A pericardial effusion is an abnormal collection of fluid in the pericardial sac. When an effusion begins to produce increased pressure great enough to impair filling of the heart, cardiac tamponade has developed. Pericardial effusions can occur from a wide variety of causes, including uremia, malignancy, postmyocardial infarction, and bleeding into the pericardial space. In this case, the patient’s INR is significantly elevated and likely led to bleeding that eventually caused cardiac tamponade. Echocardiography is considered the preferred modality for diagnosis of cardiac tamponade. Features indicating true tamponade include compression of the right atrium and diastolic compression of the right ventricle. The compression of the right atrium typically happens during end-diastole and systole. It is important to note that, by convention, systole and diastole refer to ventricular systole and diastole. Figure 28.5A shows systolic collapse of the right atrium. Right atrial collapse for more than one-third of the duration of cardiac cycle (Figure 28.5B) is very specific for tamponade. Specifically, diastolic compression of the right ventricle is more sensitive and specific for tamponade.

1. Appleton C, Gillam L, Koulogiannis K. Cardiac tamponade. Cardiol Clin. 2017;35(4):525-537.

6. Correct Answer: C. Pressure half-time of 190 ms via CWD

Rationale: Short pressure half-time measurements (<200 ms) in the setting of AR are reflective of rapid decay of the regurgitant jet flow, due to LV pressure equalization. Holodiastolic flow reversal in the descending aorta is thought to become more indicative of a marker of severe AR the more distal it is found, so severe regurgitation is more likely when the flow reversal is seen in the abdominal aorta as compared to the proximal descending aorta. A regurgitant volume 60 mL or more per heart beat suggests severe AR. Similarly, a regurgitant fraction of 50% or more per heart beat suggests severe AR. Vena contracta is not a component of the American Society of Echocardiography (ASE) guidelines for the assessment of prosthetic aortic valve regurgitation severity.

1. Zoghbi WA, Chambers JB, Dumesnil JG, et al. Recommendations for evaluation of prosthetic valves with echocardiography and Doppler ultrasound. J Am Soc Echocardiogr. 2009;22:975-1014.

7. Correct Answer: A. Supraphysiologic cardiac output/high-flow state

Rationale: Measured Doppler gradients through cardiac valves are dependent on blood flow; elevated heart rates and blood flows will raise gradients. While malalignment of the Doppler flow may alter accuracy of gradients, averaging multiple measurements helps avoid single sample errors. Pulmonary vein flow is low velocity (<1 m/s) and typically has a Doppler “envelope” image that is different than that seen in Doppler mitral valve flow. Use of pulsed-wave Doppler would likely create aliasing in the setting of high flow velocities, requiring a change to CWD assessment.

1. Mahmood F, Matyal R, Mahmood F, Sheu RD, Feng R, Khabbaz KR. Intraoperative echocardiographic assessment of prosthetic valves: a practical approach. J Cardiothorac Vasc Anes. 2018 Apr;32(2):823-837.