M-mode echocardiography Flashcards
Which leaflets of the tricuspid valve are visualized on the apical 4-chamber view?
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.
Calculation of left ventricular (LV) mass on the basis of M-mode echocardiography assumes that the geometry of the LV is?
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 short-axis 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.
Which parameter of systolic function is independent of ventricular preload?
End-systolic volume
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.
In which condition would auscultation reveal a soft first heart sound?
Mitral stenosis.
Calcific aortic stenosis.
Right bundle branch block.
First-degree AV block.
1st degree AV block
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 , 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.
According to the American Society of Echocardiography guidelines, LV chamber dimensions on two-dimensional echocardiography should be measured?
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.
Which statement concerning echocardiographic quantitation of LV volumes is true?
LV volumes are usually similar to contrast angiographic volumes.
LV volumes are usually smaller than contrast angiographic volumes.
LV volumes are usually greater than contrast angiographic volumes.
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.
In which condition would you expect to see normal motion of the interventricular septum (IVS) on M-mode?
Right ventricular (RV) pacing.
Severe tricuspid regurgitation.
Atrial septal defect.
Aortic valve replacement.
Aortic insufficiency.
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.
In which condition is LV mass index expected to be lowest?
Mitral stenosis.
Ventricular septal defect with a significant left to right shunt.
Chronic severe aortic regurgitation.
Chronic severe mitral regurgitation due to mitral valve prolapse
Mitral stenosis. Choices B–D will result in LV dilation, but choice A does not. Since the LV mass formula depends on chamber size, a large LV will usually be associated with a large LV mass index.
Of the following M-mode signs, which is most specific to suggest the presence of cardiac tamponade?
Right atrial inversion for less than one-third of the cardiac cycle.
Plethora of the inferior vena cava.
Rapid mitral ejection fraction (EF) slope.
Right ventricular diastolic collapse.
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 one-third 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.
Which of the following conditions is most likely to be associated with pseudodyskinesis seen on two-dimensional echocardiography?
Atrial septal defect.
Liver disease.
Constrictive pericarditis.
Coronary heart disease.
Left bundle branch block.
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.
Which of the following statements concerning M-mode echocardiography is true?
It is a two-dimensional technique.
Sampling rate exceeds 1,000 samples per second.
Sampling rate approaches 100 samples per second.
Lateral resolution is superior to axial resolution.
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.
What may be said about this patient’s hemodynamic state?
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.
A 54-year-old man undergoes echocardiography (M-mode)
He has severe hypertension refractory to three drugs. He has no history of coronary or valvular heart disease. His septal and posterior wall thickness are 12 mm and his end-diastolic dimension is 44 mm. His left ventricular (LV) mass index is 92 g/m2.
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.
This M-mode is taken from the study of a 59-year-old man who presents with severe heart failure symptoms . You would expect his examination to show:
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.
Based on this pulsed-wave spectral Doppler profile taken in the right ventricular outflow tract just prior to pulmonary valve , which of the following findings on an M-mode recording of the pulmonary valve would be expected?
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
A 56-year-old man presents to the hospital with progressive shortness of breath. Based on the results of the recorded M-mode echocardiogram which of the following conclusions can be drawn?
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.
A 60-year-old woman with a history of rheumatic fever and progressive shortness of breath with exertion is seen in follow-up and the following M-mode images were obtained
The patient has rheumatic mitral stenosis. The most characteristic feature is a reduced E-F slope (Fig. 3-29A; white arrow) seen on M-mode through the mitral valve. The normal mitral valve M-mode “M” shape is lost because of a reduction in early diastolic filling. In addition, as the M-mode cursor is moved to the LV cavity (Fig. 3-29B), a characteristic prominent early diastolic dip (white arrow head) of mitral stenosis can be seen as well as paradoxical anterior motion of the septum in systole (dotted white arrow).
A 72-year-old woman with breast cancer and with shortness of breath presents to the emergency room. M-mode images are obtained from the parasternal long-axis and subcostal views
There is RV chamber collapse consistent with cardiac tamponade. M-mode of the RA and RV aids in the diagnosis of cardiac tamponade due to the high temporal resolution allowing for timing the duration of chamber collapse . Although RA chamber collapse >1/3 of the cardiac cycle is typically more sensitive than RV chamber collapse >1/3 of the cardiac cycle, the latter is much more specific. Therefore, although this patient has only a brief period of RA chamber collapse during systole, which is <1/3 of the cardiac cycle, there is prolonged RV chamber collapse >1/3 of the cardiac cycle (dotted arrow) consistent with cardiac tamponade.
This M-mode is taken from the study of an 86-year-old woman with shortness of breath and fatigue. She underwent a medical procedure approximately 4 months prior to her presentation with shortness of breath. What was the medical procedure?
Insertion of a permanent pacemaker for chronotropic incompetence. This patient developed a pacemaker-related left bundle branch block. In normal activation, the normal downward motion of the septum slightly precedes the peak upward motion of the posterior wall. This is illustrated below in Figure , on which is drawn a vertical dotted line, which illustrates that the peak downward or posterior motion of the interventricular septum is slightly earlier than the peak anterior motion of the posterior wall.
By contrast, this M-mode illustrates the classic features of left bundle branch block. In this instance, there is an early downward septal motion (vertical dotted line) and after a significant delay, peak upward motion of the posterior wall (solid arrow).
A 70-year-old woman collapses after a heated argument with her son. At presentation to the emergency room, she is complaining of chest pressure, is severely hypotensive, and has a loud holosystolic murmur. She is taken to the catheterization suite where she is found to have no obstructive coronary disease. A transesophageal echocardiography is performed, from which the following M-mode is obtained. What is the most likely explanation for her severe hypotension and systolic murmur?
Dynamic outflow tract obstruction. This patient had a stress cardiomyopathy with severe LV dysfunction and developed acute LV outflow tract obstruction. The harsh murmur was due to either dynamic obstruction or mitral regurgitation, which itself resulted from systolic anterior motion of the mitral valve. The M-mode clearly demonstrates mid systolic closure of the aortic valve (arrow). This mid systolic closure is caused by obstruction to LV outflow. The base of the heart is not only involved in the stress cardiomyopathy-related LV dysfunction, but, in fact, is hyperdynamic.
A is incorrect, as there is no evidence for a bacterial vegetation demonstrated on this still frame. C is also incorrect; while the aortic valve may close prematurely in acute severe mitral regurgitation, the clinical scenario fits better with dynamic outflow tract obstruction. Finally D is incorrect; while fixed subaortic obstruction due to a subaortic membrane also features abnormality in the aortic valve envelope, the opening and closing tend to be confined to the very early part of systole.
A 66-year-old woman with chest pain and shortness of breath presents to the hospital. A heart murmur is auscultated. The medical team caring for the patient requests an echocardiogram to evaluate her heart murmur. Based on the findings on this M-mode recording , which of the following descriptions would best characterize her heart murmur?
The M-mode recording demonstrates mid to late systolic prolapse of the mitral valve (arrow; solid line identifies onset of mid-systole) consistent with mitral regurgitation occurring in mid to late systole as shown on the accompanying continuous wave Doppler spectral profile (; onset systole solid arrow; mitral regurgitation stippled arrow) and still frame color-flow Doppler images (Fig. 3-25C,D) in early and late systole (note accompanying ECG recordings for timing), respectively. A holosystolic murmur would not be expected, given these M-mode findings. An early diastolic murmur with soft S1 would be expected with acute, severe aortic regurgitation; in this case, the M-mode recording does not show characteristic findings such as diastolic fluttering of the mitral leaflets or early closure of the mitral valve. With a diastolic rumble and prominent (loud) S1, mitral stenosis would be the expected pathology; findings of mitral stenosis are not demonstrated on this M-mode tracing. A characteristic finding with hypertrophic obstructive cardiomyopathy is a systolic ejection murmur that augments with performance of a Valsalva maneuver; characteristic findings such as systolic anterior motion of the anterior mitral leaflet and septal hypertrophy are not seen on this M-mode recording of the mitral valve.
The M-mode in figure is most consistent with what abnormality?
This M-mode recording illustrates a classic case of a left atrial myxoma prolapsing into the mitral orifice with valve opening (Fig. 3-24). The tumor appears as a mass of echoes behind the mitral valve during diastole. Note the echo free space behind the anterior leaflet at the onset of diastole (thin arrows). This occurs because a time lag exists between the early diastolic opening of the valve and when the tumor mass subsequently moves into the mitral orifice. Although the mitral EF slope is diminished significantly (thick white arrow), this recording is not consistent with rheumatic mitral stenosis. The mitral leaflets are not thickened and the posterior leaflet moves normally (black arrow). Findings consistent with the presence of acute severe aortic insufficiency, such as high-frequency diastolic fluttering of the mitral valve or, possibly, the interventricular septum (depending upon jet direction) and premature mitral valve closure, are not demonstrated. With hypertrophic obstructive cardiomyopathy, increased thickness of the interventricular septum and systolic anterior motion of the mitral apparatus would be expected; these findings are not demonstrated on this M-mode recording.
A 55-year-old woman is admitted to the hospital with syncope. Based on the M-mode , what is diagnosis?
This M-mode shows evidence of systolic anterior motion of the mitral valve, a sign that is usually pathognomonic for hypertrophic obstructive cardiomyopathy. Studies have shown that 70% of patients with hypertrophic cardiomyopathy have obstruction either at rest or provoked by exercise. In hypertrophic obstructive cardiomyopathy, there is hyperdynamic systolic function, with low levels of wall stress; the LV outflow tract is narrowed by septal hypertrophy and, in some patients, by anterior displacement of the mitral valve. The arrow points to systolic anterior motion of the mitral valve with septal–mitral contact.
A 32-year-old woman is referred to you for a systolic murmur. She is completely asymptomatic. An echocardiogram is performed . Based on this M-mode recording through the aortic valve, what is your diagnosis?
The image shown features an abrupt, very early posterior motion of the right cusp of the aortic valve, which is characteristic of subaortic membrane. The mechanism for this finding is unclear. Bicuspid aortic valve motion features an eccentric closure line. Hypertrophic obstructive cardiomyopathy may have premature closure of the aortic valve on M-mode, but this tends to occur toward mid-systole, rather than early systole.
The condition most commonly associated with the M-mode finding in
his M-mode recording of the pulmonary valve illustrates the “flying-W sign”. 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.
A 56-year-old man presents to the hospital with progressive shortness of breath. Based on the results of the recorded M-mode echocardiogram , which of the following conclusions can be drawn?
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.
A 74-year-old woman presents with edema and ascites 8 years following coronary artery bypass surgery. Which of the following statements are correct regarding the following M-mode image
The patient has constrictive pericarditis. Hallmark features on M-mode include a septal shudder (see smaller white arrow) in early diastole (equivalent to the pericardial knock on physical examination and the septal bounce seen on two-dimensional imaging). There is flattening of the posterior wall in diastole (see larger white arrow pointing down) due to completion of most diastolic filling in early diastole and pericardial thickening or calcification. A respirometer is present but LV and RV cavity size do not change significantly in the limited number of beats seen in this respiratory cycle. However, this would be expected in a more prolonged tracing of inspiratory and expiratory beats.
A 37-year-old man underwent an echocardiogram due to palpitations. Which of the following statements is correct regarding this M-mode image?
This is a normal M-mode. . Characteristic M-mode findings are the E point, the E-F slope, the A-point, and the C-D closure line. The E-F slope occurs during early-mid diastolic filling, the A-point during atrial contraction, and the C-D closure line during systole.
A 42-year-old man with a history of palpitations and presyncope has the following 2 M-mode echocardiograms. On physical examination, he has a widely persistent split of the second heart sound. Which of the following statements is correct?
Findings are consistent with preexcitation. The pertinent findings on M-mode are inward movement of the posterior wall (solid white arrow) prior to the interventricular septum (dotted white arrow). This occurs because of preexcitation of the left posterior lateral wall prior to the septum due to a left posterolateral accessory pathway of Wolf-Parkinson-White (WPW). On physical examination with a left-sided pathway, there is early closure of the aortic valve and therefore persistent splitting of the second heart sound. In contrast, with a right-sided accessory pathway, there is early closure of the pulmonary valve, which results in paradoxical splitting of the second heart sound.
