1. Answer: A. On two-dimensional transthoracic imaging, the septal and anterior leaflets are visualized on the apical 4-chamber view. The posterior leaflet of the tricuspid valve is most often visualized on the parasternal short-axis view.

2. Answer: B. LV mass and LV volume measurements from M-mode and two-dimensional echocardiography are based on the geometric assumptions that the ventricle is an ellipsoid with a long-axis to shortaxis ratio of 2:1. The mass formula, LV mass (g) = 0.8(1.04[(LVIDd + PWTd + SWTd)³ – LVIDd³]) + 0.6 calculates the volumes of an inner and outer ellipsoid and subtracts the inner volume from the outer volume. The resulting volume is that of a “shell” of myocardium. The volume of this shell of myocardium is then multiplied by the specific gravity of myocardium, 1.04 g/m², to yield LV mass. This geometric assumption limits the applicability of the formula to normally shaped hearts.

3. Answer: C. Virtually all parameters of systolic function (ejection fraction, dP/dt, fractional shortening, and Vcf) depend on loading conditions. Preload is the force that acts to stretch the myocardial fibers at end-diastole and is related to end-diastolic volume. By Starling law of the heart, increased preload will be associated with increased fiber stretch, and increased force of contraction. Afterload is the force that opposes LV ejection.

End-systolic volume is also a parameter of systolic function. A related concept is that at any given contractile state, the LV will contract to the same end-systolic volume even as the LV diastolic volume increases.

4. Answer: D. The degree to which the mitral valve leaflets are separated when ventricular activation closes the mitral valve is an important determinant of the loudness of the mitral component of the S1. Accordingly, in a patient with a long PR interval (choice D), the mitral and tricuspid leaflets float into a semiclosed position because of the long period between atrial contraction and ventricular activation. Mitral stenosis is characterized by a loud first sound, if the leaflets are pliable, because the transmitral gradient at end-diastole prevents the leaflets from drifting close together. Calcific aortic stenosis (by itself) or right bundle branch block do not have much of an impact on the loudness of the S1.

5. Answer: D. According to the echocardiographic chamber quantification guidelines, two-dimensional echocardiographically derived linear dimensions overcome the common problem of oblique parasternal images, resulting in overestimation of cavity and wall dimensions from M-mode. The actual visualized thickness of the ventricular septum and other chamber dimensions can be measured as defined by the actual tissue-blood interface, rather than the distance between the leading edge echoes done by M-mode.

6. Answer: B. Numerous comparison studies have shown that LV volumes derived from echocardiography are systematically smaller than those derived from contrast angiography. The two reasons for this discrepancy are that echocardiographic algorithms that utilize apical views (e.g., biplane method of discs) underestimate the true length of the LV, when compared with angiography, and that angiographic contrast fills the recesses between trabeculations, yielding a larger area.

7. Answer: E. The IVS normally moves posteriorly (leftward) in early ventricular systole. Paradoxical septal motion is an early systolic anterior (rightward) motion of the septum. Thickening of the septum still occurs. Paradoxical septal motion is associated with conditions in which there is RV volume overload, or left bundle branch block, either developed or due to RV pacing. After aortic valve replacement, or any cardiac surgery, there is prominent translation of the heart that can give the appearance of paradoxical septal motion. Aortic insufficiency, a situation in which there is LV volume overload, would not be expected to be associated with paradoxical septal motion and is therefore the correct answer.

8. Answer: A. Mitral stenosis. Choices B-D will result in LV dilation, but choice A does not. Since the LV mass formula (Question 2) depends on chamber size, a large LV will usually be associated with a large LV mass index.

9. Answer: B. The temporal resolution of M-mode echocardiography is superior to that of two-dimensional echocardiography. The high temporal resolution of M-mode echocardiography is due to the fact that this technique has a much higher sampling rate compared with two-dimensional echocardiography. For both techniques, the axial resolution is similar since the same transducer frequency is used. Lateral resolution is superior with two-dimensional echocardiography because with the M-mode technique sampling occurs only along a single scan line.

10. Answer: D. Right ventricular diastolic collapse. Right atrial inversion and plethora of the inferior vena cava (IVC) are sensitive signs suggesting increased intrapericardial pressures, but they are not the most specific signs suggesting cardiac tamponade. When right atrial inversion extends for more than onethird of the cardiac cycle however, the reported specificity is high. Plethora of the IVC is a nonspecific marker associated with increased right atrial pressures; plethora can be observed even when the right atrial pressure is not increased as is seen with certain highly trained athletes. With inspiration, the mitral EF slope has been observed to diminish and, thus, is not rapid in the presence of cardiac tamponade. Of the choices available, right ventricular diastolic collapse is the most specific sign of cardiac tamponade.

11. Answer: B. Pseudodyskinesis is characterized by diastolic flattening of the inferior/inferolateral wall. In pseudodyskinesis, the LV has a noncircular geometry at end-diastole due to external compression, while in systole it assumes a circular appearance. Pseudodyskinesis occurs in the presence of an abdominal process such as advanced liver disease where associated ascites can cause increased intra-abdominal pressure and resultant extrinsic compression of the LV diaphragmatic wall.

12. Answer: B. The M-mode technique offers a unidimensional view of the heart. While dedicated M-mode transducers produced sampling rates of approximately 2,000 Hz, current generation transducers producing two-dimensional guided M-mode recordings sample at rates exceeding 1,000 samples per second. Current-generation two-dimensional imaging systems can produce images at frame rates approaching 100 frames per second. With M-mode echocardiography, axial resolution exceeds lateral resolution.

13. Answer: C. When measuring LV dimensions and wall thickness, either two-dimensional or M-mode techniques can be used, although two-dimensional guided measurements are preferred to avoid issues associated with oblique cuts. Measurements should be made at or immediately below the level of the tips of the mitral leaflets preferentially in the parasternal long-axis view as perpendicular to the major axis of the ventricle as possible. The Teichholz or Quinones methods of calculating LVEF from LV linear dimensions can often result in considerable inaccuracies as a result of the geometric assumptions required to convert linear measurement to three-dimensional volumes; thus, the use of linear measurements to calculate LVEF is discouraged. The biplane method of discs (modified Simpson rule) is the recommended twodimensional method for volumetric assessment of LVEF; alternatively three-dimensional echocardiography can be used for this purpose. As the left atrium is shown to have a complex shape, a single linear measurement of the anteroposterior dimension can lead to significant inaccuracy in assessing LA size. The currently recommended method to assess LA size is the biplane method of discs to determine volume.

14. Answer: D. This study was obtained in a patient with an idiopathic dilated cardiomyopathy. The M-mode echocardiogram shows marked LV dilation, with an end-diastolic dimension approaching 6 cm and an end-systolic dimension of 5.5 cm. The fractional shortening is therefore low. There is a large separation between the anterior leaflet of the mitral valve and the septum (the e-point septal separation, since the peak anterior position of the anterior leaflet is known as the e point in M-mode parlance). This sign is associated with a low forward stroke volume. It is important to realize that LV dilation by itself does not lead to an abnormal e-point septal separation. An individual with severe aortic regurgitation might have a dilated LV but normal fractional shortening. In that case, the e-point septal separation would be normal.

As for the incorrect choices, while this patient might have high left ventricular end diastolic pressure (LVEDP), there is no definite evidence for this. The pathognomonic M-mode sign of this physiology, the so-called “a-c shoulder” or “b-bump,” is not present. Figure 3-19 shows a prominent b bump (see the arrow).

Finally, the etiology of the LV dysfunction shown in this case could have been chronic aortic regurgitation, with the development of contractile failure, but this M-mode tracing is not specific for such a cardiomyopathy. The lack of fluttering of the mitral leaflets provides some evidence against significant aortic regurgitation.

15. Answer: A. This patient’s LV mass index is normal, by the partition values in the ASE quantitation guidelines, so he does not have left ventricular hypertrophy. According to the pioneering work of Ganau et al., and as recommended by the ASE quantitation guidelines, the combination of a high relative wall thickness with a normal LV mass index is termed concentric remodeling. This individual clearly has an elevated relative wall thickness, defined as (2 × PWTd)/LVIDd with the upper limit of normal 0.42 (for this patient 0.55). The term concentric hypertrophy refers to an elevated LV mass index (i.e., greater than 95 g/m² in women, greater than 115 g/m² in men) and a high relative wall thickness.

According to the work by Wachtell and coworkers, most individuals with hypertension and evidence of remodeling, as the case with this individual, have abnormalities in diastolic filling.

The M-mode clearly shows normal fractional shortening; while this is not necessarily the same as a normal individual, the absence of a coronary heart disease by history argues that global EF is normal.

16. Answer: B. The M-mode shows a classic example of early mitral valve closure, which is pathognomonic of acute severe aortic regurgitation. There is also LV dilation and a generous e-point septal separation. The early closure of the mitral valve is caused by the rapid equilibration of LV diastolic pressure and aortic diastolic pressure and for this reason the murmur will not be holodiastolic. Patients with acute severe aortic regurgitation are likely to have evidence of elevated filling pressure and rales. An opening snap is heard in patients with rheumatic mitral stenosis with pliable leaflets. This is not the echocardiogram of such a patient. An apical systolic murmur implies mitral regurgitation and there is no suggestion that this patient has coexisting mitral regurgitation.

17. Answer: C. This display of the pulse-wave spectral Doppler tracing with the sample volume placed in the RV outflow tract just prior to the pulmonary valve orifice shows a rapid pulmonary acceleration time (stippled lines; 61 ms) and a mid-systolic notch (arrow). This pattern is consistent with the presence of severe pulmonary artery hypertension (PAH). Although not often obtained in contemporary echocardiography practice, an M-mode cursor can be directed across the posterior leaflet of the valve and produce a recording in such a patient with chronic severe PAH in sinus rhythm characterized by a diminutive or absent A-wave, a prolongation of the preejection period, and mid-systolic notching (“flying-W sign”). This latter finding is a specific indicator of the presence of PAH. An exaggerated (prominent) A wave may be seen with valvular pulmonary stenosis but is not seen with severe PAH. Among patients with severe RV failure, the A wave may reappear. The presence of an A wave will not be found in patients with atrial fibrillation (see Fig. 3-20).

18. Answer: B. This 56-year-old man presented with symptoms and signs of heart failure. This M-mode echocardiogram is recorded through the mitral leaflet tips (Fig. 3-21). This recording shows significantly increased LV cavity dimensions in systole and diastole (stippled arrows), a significantly increased e-point septal-separation distance (stippled lines), and interrupted AC closure of the mitral valve echocardiogram. The findings of this M-mode echocardiogram suggest that very poor systolic performance is present. The LV cavity is dilated and the LV ejection fraction is severely reduced. Stroke volume is severely reduced as indicated by the increased e-point septal-separation distance (normal <7 mm). The LV end-diastolic pressure is elevated as indicated by the presence of the interrupted AC closure or “B-bump.” The mean left atrial pressure, although likely elevated, cannot be derived from the information presented.

19. Answer: C. This two-dimensional video and the accompanying M-mode recording illustrate findings of pseudodyskinesis, a condition that may be confused with infarction of the inferior/inferolateral wall. Pseudodyskinesis, in which systolic wall thickening (as shown by the M-mode recording and accompanying real-time video of the M-mode and two-dimensional images) is preserved, is characterized by diastolic flattening of the inferior/inferolateral wall followed by systolic rounding and again outward diastolic bulging caused by extrinsic compression. As illustrated in the accompanying short-axis video, the LV is shown to have a noncircular geometry at end-diastole consistent with the existence of extrinsic compression, while in systole the LV assumes a circular appearance. This circular appearance of the LV in systole would not be expected in the presence of a myocardial infarction. Paradoxical motion of the interventricular septum (IVS) occurs in the presence of RV volume overload; in this condition, echocardiography would show the IVS to flatten in diastole and assume a rounded contour in systole with motion toward the RV. A septal bounce, as occurs with constrictive pericarditis, is characterized by an early to mid-diastolic dip(s) in which the septal motion reflects right then LV filling in diastole. Dyssynergy, another condition in which an apparent wall motion abnormality may be confused with that caused by ischemic heart disease, occurs typically in the setting of LBBB and is characterized on the M-mode recording by an early systolic downward motion during isovolumic contraction and paradoxical motion toward the RV during systole followed by an exaggerated early diastolic dip. In this case study, motion of the IVS is normal as shown on the two-dimensional and M-mode recordings.

20. Answer: A. This M-mode recording of the pulmonary valve illustrates the “flying-W sign” (Fig. 3-22). The normal pulmonary valve M-mode is characterized by presystolic a-wave with motion away from the transducer followed by further posterior motion of the valve leaflet during systole. With chronic severe pulmonary hypertension, a characteristic appearance to the M-mode tracing, termed “the flying-W sign,” may be generated. This tracing is characterized by the loss of the a-wave (solid arrows) and mid-systolic notching (stippled arrow). With pulmonary valve stenosis, the a-wave is characteristically preserved, or even accentuated, and mid-systolic notching is not observed. In a pure right-sided heart volume load state, such as occurs with primary tricuspid regurgitation, one would not expect pulmonary hypertension to be present and thus the pulmonary valve M-mode tracing should not be altered significantly. Among patients with acute pulmonary embolism, the level of elevation of the pulmonary artery pressure does not usually exceed 50 mm Hg and thus the M-mode findings of chronic severe pulmonary arterial hypertension would not be expected to be observed.