1. Correct Answer: B. Hypertrophic cardiomyopathy

Rationale: Continuous-wave Doppler pattern for LVOT obstruction seen in hypertrophic cardiomyopathy is described as “dagger shaped,” with gradual increase in velocity in early systole with acceleration to peak velocity in mid-systole. LV pressure outflow gradient may be estimated using modified Bernoulli equation: ΔP = 4v², where ΔP = pressure gradient in mm Hg and v=maximal flow velocity in m/s. The continuous-wave Doppler pattern of aortic stenosis, which is a fixed rather than dynamic lesion, demonstrates a more rounded appearance with a peak in early to mid-systole. Mitral stenosis will present with a low-pitched diastolic murmur best heard at the apex, rather than a systolic murmur as demonstrated with our patient. Echocardiographic evaluation of mitral stenosis includes visualization of a laminar, high-velocity jet at the level of the narrowing. Distally, the flow pattern will become disorganized with multiple directions of blood flow. Takotsubo cardiomyopathy is an acute, stress-induced cardiomyopathy characterized by reversible ballooning of the LV apex. Patients will present with low cardiac output and symptoms that mimic acute coronary syndromes. Echocardiographic examination will not reveal increased gradient across the LVOT.

1. Chatterjee D. Mitral valve disease: clinical features focusing on auscultatory findings including auscultation of mitral valve prolapse. Eur Soc Cardiol. 2019;16:1-10.

2. Maron MS, Rowin EJ, Maron BJ. How to image hypertrophic cardiomyopathy. Circ Cardiovasc Imaging. 2017;10:1-15.

3. Panza JA, Petrone RK, Fananapazir L, Maron BJ. Utility of continuous wave doppler echocardiography in the noninvasive assessment of left ventricular outflow tract pressure gradient in patients with hypertrophic cardiomyopathy. J Am Coll Cardiol. 1992;19:91-99.

4. Salustri A, Almaghrabi A. Mitral valve disease: correlation between the most important echocardiographic parameters and hemodynamics. e-J Cardiol Pract. 2019;16(24):1-20.

5. Wahab A, Wahab S, Panwar R, Alvi S. Takotsubo cardiomyopathy or broken heart syndrome. Iran Cardiovasc Res J. 2010;4:33-34.

2. Correct Answer: C. Intravenous fluid

Rationale: Systolic anterior motion (SAM) of the mitral valve is characterized by the anterior displacement of the anterior leaflet of the mitral valve during systole, leading to LVOT obstruction and MR (Figure 45.28). SAM occurs in 4% to 5% of patients following mitral valve repair. Predisposing factors include redundant leaflet tissue, a short distance between ventricular septum and mitral valve coaptation point or coaptation-septum (CS) distance following repair, and a nondilated, hyperdynamic ventricle. SAM may present with varying clinical significance. Many patients are asymptomatic removed for brevity while other patients may have pulmonary congestion and hemodynamic collapse due to LVOT obstruction and severe MR.

The patient in this question is demonstrating hemodynamic and echocardiographic signs of moderate to severe SAM, characterized by low cardiac output, severe MR, and LVOT obstruction. Once the diagnosis of SAM has been made, treatment can be initiated. Reduced inotropic support and volume loading are first-line medical therapy for SAM and associated LVOT obstruction. Volume loading serves to both distend the LV dimensions and to enhance the CS distance. Administration of the diuretic furosemide would worsen intravascular volume depletion. Initiation of milrinone would potentiate the hyperdynamic cardiac condition, which may lead to increased severity of symptoms. Mitral valve replacement may be necessary in the event of severe SAM refractory to medical management, but is not a first-line therapy.

1. Manabe S, Kasegawa H, Arai H, Takanashi S. Management of systolic anterior motion of the mitral valve: a mechanism-based approach. Gen Thorac Cardiovasc Surg. 2018;66:379-389.

2. Sternik L, Zehr KJ. Systolic anterior motion of the mitral valve after mitral valve repair: a method of prevention. Texas Hear Inst J. 2005;32:47-49.

3. Correct Answer: A. Ventricular septal defect

Rationale: Ventricular septal rupture (VSR) is a dramatic complication following an acute myocardial infarction (AMI). Post-MI VSR occurs when the acutely infarcted tissue at the myocardial infarct border zone ruptures or tears. Incidence of post-MI VSR has a bimodal distribution with peaks within the first 24 hours and again between 3 and 5 days, but can occur as late as 2 weeks following an acute MI. The majority of cases of myocardial rupture are associated with complete occlusion of a major coronary artery.² Other risk factors include older age, female sex, history of hypertension, nonsmoker, and anterior infarction.³

With the increased use of percutaneous intervention, the incidence of post-MI VSR has decreased, but the associated mortality rate remains high (94% with conservative medical management and 47% with surgical management). Patients with post-MI VSR may present with the abrupt onset of dyspnea, hypotension, and development of a new murmur. Acute decompensation is due to pulmonary edema, biventricular failure, and cardiogenic shock.

Echocardiography may be used to detect VSR. Two-dimensional color Doppler can detect flow through the defect and is particularly helpful if the septal defect is small or the communicating tract takes a tortuous path (Figure 45.29).

1. Crenshaw BS, Granger CB, Birnbaum Y, et al. Risk factors, angiographic patterns, and outcomes in patients with ventricular septal defect complicating acute myocardial infarction. Circulation. 2000;101:27-32.

2. Evrin T, Unluer EE, Kuday E, et al. Bedside echocardiography in acute myocardial infarction patients with hemodynamic deterioration. J Natl Med Assoc. 2018;110:396-398.

3. Manabe S, Kasegawa H, Arai H, Takanashi S. Management of systolic anterior motion of the mitral valve: a mechanism-based approach. Gen Thorac Cardiovasc Surg. 2018;66:379-389.

4. Suder B, Janik L, Wasilewski G, et al. Post-myocardial infarction ventricular septal defect. Is it better to operate on a fresh infarction or to wait? A case study. Kardiochirurgia i Torakochirurgia Pol. 2016;13:39-41.

4. Correct Answer: D. No intervention for PE

Rationale: Figure 45.4 shows a near-field clutter artifact, which is created by high-amplitude reflections from the piezoelectric crystals themselves. While challenging, it may be distinguished from a true structure by its hazy appearance and ill-defined borders. Additionally, artifacts should not produce interruption of color Doppler flow or sonographic contrast, as seen with true structures. The ability to distinguish between artifact and thrombus is critical as this distinction may help to guide therapy and avoid unnecessary invasive treatment.

PE is an unfortunate perioperative complication following major surgical procedures and is one of the leading causes of intraoperative cardiac arrest. While a CT pulmonary angiogram is the definitive diagnostic test, TEE has been shown to detect PE in over 50% of patients and may be beneficial in the hemodynamically unstable patient. Indirect signs of PE on TEE include RV dilation with hypokinesis, a D-shaped interventricular septum indicative of RV pressure overload, and severe TR. Importantly, these findings are not specific for PE. Additionally, McConnell sign is an echocardiographic finding with a distinct pattern of RV dysfunction characterized by RV free wall akinesis with preserved apical function, which is characteristic of acute PE. These indirect echocardiographic signs of PE are of great clinical value as some studies indicate that direct visualization of thromboemboli is as low as 26%.⁶ Figure 45.30 and the aforementioned findings may also help to differentiate between acute and chronic PE.

1. De Vos L, De Herdt V, Timmermans F. Misdiagnosis or missed diagnosis: digging out the “near-field clutter” artifact in a patient with stroke. CASE. 2020;4:2-6.

2. Lau G, Ther G, Swanevelder J. McConnell’s sign in acute pulmonary embolism. Anesth Analg. 2013;116:982-985.

3. Liang Y, Alvis B, Rice MJ, Shaw AD, Deitte LA, Eagle S. A near-field clutter artifact mimicking pulmonary thrombus during transesophageal echocardiography. Anesth Analg. 2016;123:831-833.

4. Pamnani A, Skubas NJ. Imaging artifacts during transesophageal echocardiography. Anesth Analg. 2014;118:516-520.

5. Pruszczyk P, Torbicki A, Kuch-Wocial A, Szulc M, Pacho R. Diagnostic value of transesophageal echocardiography in suspected hemodynamically significant pulmonary embolism. Heart. 2001;85:628-634.

6. Rosenberger P, Shernan S, Weissmuller T, Eltzschig HK. Role of intraoperative transesophageal echocardiography for diagnosis and managing pulmonary embolism in the perioperative period. Anesth Analg. 2005;100:292-293.

5. Correct Answer: B. RV collapse in diastole

Rationale: Figure 45.5 is a transthoracic parasternal long-axis view (PLAX) demonstrating collapse of the right ventricle during diastole. Bedside echocardiography is an excellent initial imaging modality when cardiac tamponade is suspected and is recommended by the American College of Cardiology, the American Heart Association, and the American Society of Echocardiography (ASE). A focused examination for cardiac tamponade should include determination of size and extent of the pericardial effusion, collapsibility of cardiac chambers, ventricular interdependence with respiration, dilation of the IVC with limited respiratory variation, and a septal “bounce.” Among these findings, RA collapsibility for over one-third of the cardiac cycle is perhaps the most reliable sign of cardiac tamponade with a near 100% specificity and 94% sensitivity. M-mode echocardiography may be used to assess RV collapse, which will occur in diastole and persist as long as pericardial pressures are higher than RV filling pressures. A greater duration of RV collapse corresponds to more significant tamponade.

Beck’s triad consisting of hypotension, jugular venous distention and muffled heart sounds is present in only a minority of those with cardiac tamponade. Sinus tachycardia is a compensatory mechanism to allow at least partial maintenance of cardiac output. Pulsus paradoxus is a drop in systemic BP by >10 mm Hg with inspiration and occurs due to exaggerated ventricular interdependence. Increased RV filling during inspiration leads to bulging of the RV into the LV resulting in decrease in LV filling and SV.

1. Cheitlin MD, Armstrong WF, Aurigemma GP, et al. ACC/AHA/ASE 2003 guideline update for the clinical application of echocardiography: Summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/ASE Committee to Update the 1997 Guidelines for the Clinical Application of Echocardiography). Circulation. 2003;108:1146-1162.

2. Beck C. Two cardiac compression triads. J Am Med Assoc. 1935;104:714.

3. Fitchett D, Sniderman A. Inspiratory reduction in left heart filling as a mechanism of pulsus paradoxus in cardiac tamponade. Can J Cardiol. 1990;6:348.

4. Gillam LD, Guyer DE, Gibson TC, King ME, Marshall JE, Weyman AE. Hydrodynamic compression of the right atrium: a new echocardiographic sign of cardiac tamponade. Circulation. 1983;68:294-301.

5. Pérez-Casares A, Cesar S, Brunet-Garcia L, Sanchez-de-Toledo J. Echocardiographic evaluation of pericardial effusion and cardiac tamponade. Front Pediatr. 2017;5:1-10.

6. Correct Answer: A. Right atrial (RA) collapse during systole

Rationale: RA inversion/collapse beginning at end-diastole and continuing through some portion of systole has a 100% sensitivity for cardiac tamponade (Figure 45.31). When the duration of RA collapse is greater than one-third of the cardiac cycle, the specificity of this finding for tamponade increases to 94%. Collapse of the left atrium may occur with cardiac tamponade but is much less common than RA collapse. Collapse of the RV free wall occurs during diastole because of increases in pericardial pressure. With moderate increases in pericardial pressure, this may be observed in expiration only, but as the effusion increases in severity, collapse may be seen throughout the respiratory cycle. Collapse of the left ventricle is much less common due to its thick wall, but may be seen with a loculated pericardial effusion around the posterior wall, which can be seen following cardiac surgery.

1. Gillam LD, Guyer DE, Gibson TC, King ME, Marshall JE, Weyman AE. Hydrodynamic compression of the right atrium: a new echocardiographic sign of cardiac tamponade. Circulation. 1983;68:294-301.

2. Gillebert C, Van Hoof R, Van De Werf F, Piessens J, De Geest H. Abnormal wall movements of the right ventricle and both atria in patients with pericardial effusion as indicators of cardiac tamponade. Eur Heart J. 1986;7:437-443.

3. 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.

4. Pérez-Casares A, Cesar S, Brunet-Garcia L, Sanchez-de-Toledo J. Echocardiographic evaluation of pericardial effusion and cardiac tamponade. Front Pediatr. 2017;5:1-10.

7. Correct Answer: A. Decrease LVAD pump speed

Rationale: LVADs are the most common mechanical circulatory assist devices used for severe heart failure. They may be utilized as a bridge to transplant, recovery or decision-making, or as destination therapy in those not eligible for transplantation.

The TEE (Figure 45.32) demonstrates RV dilation and a small, decompressed LV cavity. These findings are suggestive of a suction event. Suction events occur when the speed of the LVAD pump is excessive relative to LV filling. This results in exaggerated LV offloading and collapse of the LV cavity upon itself and the inflow cannula. Causes of suction events include low intravascular volume, RV failure, tamponade, and inflow cannula obstruction.

Echocardiographic evaluation will demonstrate a significant reduction in LV size. Evaluation of the right ventricle for signs of failure is critical as this may lead to LV underfilling and will alter long-term management. Examination of inflow cannula position should also occur as malposition of cannulas may predispose to suction events.

Immediate treatment of suction events includes slowing the device speed and administering volume. Further measures should be targeted at underlying causes of suction events including RV dysfunction. This may be treated with inotropic support such as epinephrine, nitric oxide, or placement of an RV assist device. If cannula position is an issue, surgical repositioning may be indicated.²

1. Flores AS, Essandoh M, Yerington GC, et al. Echocardiographic assessment for ventricular assist device placement. J Thorac Dis. 2015;7:2139-2150.

2. Sen A, Larson JS, Kashani KB, et al. Mechanical circulatory assist devices: a primer for critical care and emergency physicians. Crit Care. 2016.20:1-20.

3. Slaughter MS, Pagani FD, Rogers JG, et al. Clinical management of continuous-flow left ventricular assist devices in advanced heart failure. J Hear Lung Transplant. 2010;29:S1-S39.

8. Correct Answer: C. D-shaped interventricular septum

Rationale/Critique: The echocardiographic image shown in Figure 45.7 is a midesophageal ascending aorta long-axis view. In this view, the RPA is seen in short axis in the near field with a long-axis view of the ascending aorta visualized behind. A large intravascular thrombus is seen in the RPA.

Accompanying echocardiographic findings of hemodynamically significant pulmonary emboli include RV hypokinesis, RV dilation, severe TR, and D-shaped interventricular septum. The D-shaped appearance of the left ventricle occurs due to ventricular interdependence where RV pressure or volume overload leads to mechanical flattening of the interventricular septum and bulging into the left ventricle. This alters the geometry of the left ventricle in a deleterious manner, resulting in impaired LV function.

1. Kapoor P, Muralidhar K, Nanda N, et al. An update on transesophageal echocardiography views 2016: 2D versus 3D tee views. Ann Card Anaesth. 2016;19:S56-S72.

2. Lau G, Ther G, Swanevelder J. McConnell’s sign in acute pulmonary embolism. Anesth Analg. 2013;116:982-985.

3. Liang Y, Alvis B, Rice MJ, Shaw AD, Deitte LA, Eagle S. A near-field clutter artifact mimicking pulmonary thrombus during transesophageal echocardiography. Anesth Analg. 2016;123:831-833.

4. Ma C, Cohen J, Tolpin D. Right ventricular dysfunction and the “D”-shaped left ventricle. Anesthesiology. 2020;132:155.

9. Correct Answer: A. Midesophageal bicaval

Rationale: TEE is a useful imaging modality when initiating ECMO support, both for positioning of cannulas and to promptly recognize complications, such as pericardial effusion or aortic dissection. With femoro-femoral VA ECMO cannulation, the drainage (venous) cannula is positioned near the IVC/RA junction and the reinjection (arterial) cannula is generally positioned in the distal descending aorta. The midesophageal bicaval view is used to guide femoral venous cannulation as it provides visualization of the IVC, superior vena cava (SVC), right atrium, and tricuspid valve (TV). During placement, the echocardiographer should visualize the guidewire in both the IVC and SVC to ensure that it has not migrated into the right ventricle, across an atrial septal defect, or into the coronary sinus. Optimal position of the cannula tip is in the RA just beyond the cavoatrial junction. If the cannula remains too shallow it may abut the wall of the IVC, while deep insertion risks damage to cardiac structures including the interatrial septum or TV.

1. Douflé G, Roscoe A, Billia F, Fan E. Echocardiography for adult patients supported with extracorporeal membrane oxygenation. Crit Care. 2015;19:1-10.

2. Hahn RT, Abraham T, Adams MS, et al. Guidelines for performing a comprehensive transesophageal echocardiographic examination: recommendations from the American Society of Echocardiography and the Society of Cardiovascular Anesthesiologists. J Am Soc Echocardiogr. 2013;26:921-964.

3. Pavlushko E, Berman M, Valchanov K. Cannulation techniques for extracorporeal life support. Ann Transl Med. 2017 Feb 5;5(4):70.

10. Correct Answer: A. Percutaneous LVAD

Rationale: A variety of mechanical support devices are used for the treatment of severe heart failure. These devices can be divided into three main categories: paracorporeal where the pump is located outside the body, intracorporeal with the pump inside the body, and percutaneous devices, which are small pumps inserted percutaneously.

The Impella device is a short-term, percutaneous support device that can be used for either LV or RV failure. When used for LV support, it is placed retrograde across the aortic valve via the femoral or axillary artery. The device pumps blood from the left ventricle to the ascending aorta at a rate of up to 2.5 L/min, thereby offloading the left ventricle and augmenting cardiac output. When visualized on echocardiogram, the inlet should be located 3 to 4 cm below the aortic valve and the inlet area should not contact the interventricular septum or the anterior leaflet of the mitral valve. For optimal position, the outlet should be 1.5 to 2 cm above the sinuses of Valsalva (Figure 45.33).

The IABP is positioned in the thoracic aorta with the tip distal to the left subclavian artery and the proximal portion above the takeoff of the renal arteries. ECMO cannulas will be seen on echocardiography as described in Question 9.

HeartMate III LVAD is a durable, intracorporeal mechanical assist device. It is implanted surgically, not percutaneously. Echocardiographic assessment will reveal the inflow cannula positioned in the LV apex and the outflow cannula located in either the ascending or descending aorta.

1. Mukku V, Cai Q, Gilani S, Fujise K, Barbagelata A. Use of Impella ventricular assist device in patients with severe coronary artery disease presenting with cardiac arrest. Int J Angiol. 2012;21:163-166.

2. Sen A, Larson JS, Kashani KB, et al. Mechanical circulatory assist devices: a primer for critical care and emergency physicians. Crit Care. 2016;20:1-20.

3. Sponga S, Benedetti G, Livi U. Short-term mechanical circulatory support as bridge to heart transplantation: paracorporeal ventricular assist device as alternative to extracorporeal life support. Ann Cardiothorac Surg. 2019;8:143-150.

4. Stainback RF, Estep JD, Agler DA, et al. Echocardiography in the management of patients with left ventricular assist devices: recommendations from the American Society of Echocardiography. J Am Soc Echocardiogr. 2015;28:853-909.

11. Correct Answer: D. Pneumothorax

Rationale: Lung ultrasound is an increasingly utilized point-of-care technique to evaluate acute respiratory failure. Lung ultrasound relies upon the interpretation of artifacts as lung parenchyma is largely composed of air with rapidly dispersed ultrasound waves. In normal lung tissue, the pleura is the only visualized structure that will appear as a hyperechoic horizontal line. Lung sliding is the phenomenon by which the pleural line moves in synchrony with respiration.³ Lung sliding can be confirmed using M-mode, which will demonstrate a stratified, motionless pattern above the pleura and a sandy pattern representing movement of the lung below the pleura. A-lines are hyperechoic, horizontal lines that represent normal reverberation artifacts from the pleura. They occur at regular intervals and are a sign of air within the lung parenchyma. B-lines are a reverberation artifact that appear as hyperechoic vertical lines arising from the pleural line and extend to the bottom of the screen without fading. The presence of multiple B-lines is a sign of pathology as they occur when there is increased density of the lung parenchyma due to excessive fluid or collagen content. Consolidation of the lung parenchyma, whether due to infection, infarction, fluid collection, atelectasis, or mass, will appear as a solid structure, similar to liver tissue and often referred to as hepatization.

Pneumothorax manifests with absent lung sliding, confirmed with the “stratosphere” or “barcode” sign in M-mode, which indicates absence of motion (Figure 45.34A). This is in contrast to the “seashore” sign that has clear contrast between immobile chest wall above the pleura and dynamic lung tissue below the pleura (Figure 45.34B). A lung point is the transition point between normal lung tissue and an area of pneumothorax with the absence of lung sliding and B-lines.

A pleural effusion will appear as an anechoic or hypoechoic area between two layers of pleura.² Pneumonia manifests as an area of parenchymal consolidation. With large areas of consolidation, air bronchograms may be present as branching, echogenic structures. B-lines may be present in nearby tissue, often as a manifestation of inflammatory edema. Complicated pneumonia may have associated pleural effusion. The presence of B-lines demonstrates pulmonary edema.

1. Gargani L, Volpicelli G. How I do it: lung ultrasound. Cardiovasc Ultrasound. 2014;12:1-10.

2. Lichtenstein D. Lung ultrasound in the critically ill. Ann Intensive Care. 2014;4:2-12.

3. Saad MM, Kamal J, Moussaly E, et al. Relevance of B-Lines on lung ultrasound in volume overload and pulmonary congestion: clinical correlations and outcomes in patients on hemodialysis. CardioRenal Med. 2018;8:83-91.

4. Ziskin MC, Thickman DI, Goldenberg NJ, Lapayowker MS, Becker JM. The comet tail artifact. J Ultrasound Med. 1982;1:1-7.

12. Correct Answer: C. LAD coronary artery

Rationale: TTE may be used to rapidly identify regional wall motion abnormalities (RWMA) in patients with suspected acute coronary syndrome. Evaluation of the left ventricle in PLAX, parasternal short-axis view (PSAX), and apical four-chamber view (A4C) allows the echocardiographer to identify RWMAs in the territories of all three major coronary arteries. An anterior wall abnormality suggests involvement of the LAD artery, a lateral wall abnormality suggests involvement of the circumflex artery (CX), and an inferior wall abnormality suggests involvement of the RCA. This is a simplification of the 17-segment evaluation based on the ASE guidelines (see Figure 22.13), but does allow for more rapid evaluation of RWMAs.

Figure 45.10 is an apical two-chamber view with an arrow pointing to the anterior wall, which is supplied by the LAD artery.

1. Frenkel O, Riguzzi C, Nagdev A. Identification of high-risk patients with acute coronary syndrome using point-of-care echocardiography in the ED. Am J Emerg Med. Elsevier Inc. 2014;32:670-672.

2. Gibson R, Bishop H, Stamm R, Crampton RS, Beller GA, Martin RP. Value of early two dimensional echocardiography in patients with acute myocardial infarction. Am J Cardiol. 1982;49:1110-1119.

3. 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;28:1-39.

13. Correct Answer: C. Epinephrine

Rationale: Figure 45.11 shows a transgastric midpapillary short-axis view on TEE. The interventricular septum is flattened and bulging into the left ventricle, often described as a D-shaped ventricle ( Video 45.2). This alters the geometry of the left ventricle, restricting its ability to fill adequately during diastole and leading to impaired ventricular function. This finding is consistent with RV pressure or volume overload, as may be seen with PE or pulmonary hypertension. The clinical scenario of a postoperative patient raises the suspicion for a thromboembolic event.

Immediate therapy should focus on treating hemodynamic compromise and supporting the struggling right ventricle. While fluid administration is often part of the initial treatment for undifferentiated shock, in patients with known RV dysfunction, fluid administration may lead to increased RV end-diastolic pressure (RVEDP), thereby worsening RV coronary perfusion pressure and placing the right ventricle at risk for ischemia. Medical therapy should be directed by enhancing RV function through increased inotropy and increased mean arterial pressure without dramatically increasing pulmonary vascular resistance. While milrinone will enhance inotropy, it will also lead to peripheral vasodilation and worsen systemic hypotension. Metoprolol would result in a deleterious drop in HR with subsequent decrease in cardiac output; therefore, epinephrine is the best treatment choice.

1. Ma C, Cohen J, Tolpin D. Right ventricular dysfunction and the “D”-shaped left ventricle. Anesthesiology. 2020;132:155.

2. Sekhri V, Mehta N, Rawat N, Lehrman SG, Aronow WS. Management of massive and non-massive pulmonary embolism. Arch Med Sci. 2012;8:957-969.

14. Correct Answer: D. RCA

Rationale: TTE may be used to rapidly identify RWMA in patients with suspected acute coronary syndrome. Evaluation of the left ventricle in PLAX, PSAX, and A4C allows the echocardiographer to identify RWMAs in the territories of all three major coronary arteries. An anterior wall abnormality suggests involvement of the LAD artery, a lateral wall abnormality suggests involvement of the CX, and an inferior wall abnormality suggests involvement of the RCA.2 The figure demonstrates typical distributions of LAD, CX, and RCA based on ASE guidelines (see Figure 22.13).

Figure 45.12 is a PSAX with an arrow pointing to the inferior aspect of the left ventricle, which is supplied by the RCA.

1. Frenkel O, Riguzzi C, Nagdev A. Identification of high-risk patients with acute coronary syndrome using point-of-care echocardiography in the ED. Am J Emerg Med. Elsevier Inc. 2014;32:670-672.

2. Gibson R, Bishop H, Stamm R, Crampton RS, Beller GA, Martin RP. Value of early two dimensional echocardiography in patients with acute myocardial infarction. Am J Cardiol. 1982;49:1110-1119.

3. 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;28:1-39.

15. Correct Answer: A. 2 cm distal to left subclavian artery

Rationale: IABPs are frequently used for hemodynamic support in patients with cardiogenic shock or during high-risk coronary intervention. They may be inserted percutaneously via the femoral, subclavian, or axillary artery. The balloon inflates during diastole simultaneously with aortic valve closing, resulting in increased propulsion of blood from thoracic aorta to peripheral circulation. The balloon rapidly deflates with opening of the aortic valve in systole, resulting in a decrease in afterload. The decrease in afterload is thought to decrease myocardial oxygen consumption due to a decrease in LV wall stress. Optimal positioning of the tip of the IABP places it 2 to 3 cm distal to the left subclavian (Figure 45.35). This positioning supports optimal coronary flow while minimizing the risk of decreased perfusion to aortic arch vessels. The proximal end of the balloon should terminate above the renal arteries in order to avoid renal ischemia.

1. Hyson E, Ravin C, Kelley M, Curtis AM. Intraaortic counterpulsation balloon: radiographic considerations. Am J Roentgenol. 1977;128:915-918.

2. Weber KT, Janicki JS. Intraaortic balloon counterpulsation: a review of physiological principles, clinical results, and device safety. Ann Thorac Surg. 1974;17:602-636.

16. Correct Answer: B. B

Rationale: There are several static and dynamic parameters that may be assessed via echocardiography to estimate a patient’s volume status and fluid responsiveness. A hyperdynamic left ventricle with small end-diastolic area (<10 cm² in the PSAX) along with obliteration of the LV cavity during systole is very suggestive of hypovolemia. SV variation with respiration is used to determine volume responsiveness in mechanically ventilated patients. SV may be estimated by first obtaining the velocity-time integral (VTI, area under the curve using pulsed-wave Doppler) of the LVOT. The VTI measures the stroke distance, or how far a column of blood moves with each contraction. Next, the echocardiographer measures the LVOT diameter at the same level at which the VTI was obtained. Using the formula below it is possible to calculate the SV:

SV= VTI × CSA, where SV=stroke volume, VTI=velocity-time integral, CSA=cross-sectional area, πr²

Variation of >12% predicts fluid responsiveness.² When threshold variability is increased to >15%, the predictive value achieves sensitivity and specificity of >90%.³

When using TTE, VTI is obtained using the apical five-chamber view (A5C) while the PLAX is best to obtain LVOT diameter (Figure 45.36).

There are several limitations to the use of SV variation to predict fluid responsiveness. First, the patient must be in sinus rhythm to obtain accurate VTI calculation. Second, mechanical ventilation with high tidal volume ventilation (>8 cc/kg ideal body weight) is required with deep sedation or paralysis as spontaneous respiratory effort may lead to SV variability. Finally, patients must have a closed chest and normal intra-abdominal pressure.

1. Chew MS. Haemodynamic monitoring using echocardiography in the critically ill: a review. Cardiol Res Pract. 2012;2012:139537.

2. Miller A, Mandeville J. Predicting and measuring fluid responsiveness with echocardiography. Echo Res Pract. 2016;3:G1-G12.

3. Slama M, Masson H, Teboul JL. Respiratory variations of aortic VTI: a new index of hypovolemia and fluid responsiveness. Am J Physiol Circ Physiol. 2002;283:1729-1733.