- TTE Main Page
- Parasternal Long Axis
- Parasternal Short Axis
- Mass/Volume Calculations
Transthoracic echocardiography (TTE) is the most commonly performed cardiac ultrasound examination. A high quality transthoracic echocardiogram can be performed quickly at the bedside and has the potential to comprehensively evaluate left and right ventricular systolic and diastolic function, regional wall motion, valvular heart disease, and diseases of the pericardium.
The transthoracic echocardiogram has been largely standardized across institutions, such that images are generally obtained from at least 4 separate standard transducer positions which allow for different portions of the heart to be visualized in detail. These standard positions are the parasternal position (which has both long axis and short axis views), apical position , subcostal position and the suprasternal notch position. These transducer positions and the multiple views obtained from each position are described in detail on the individual section pages. Click on the tabs above to view these pages.
In addition to appreciating the power of a transthoracic echocardiogram, after performing transthoracic echocardiograms you will also come to realize the limitations of this technique. Many patients will have suboptimal or in some cases minimal acoustic windows for ultrasound examination and this has been a source of much frustration for technologists and cardiology fellows. For example, patients who are obese, those who have chronic lung disease, who are imaged supine or on a ventilator, or those who are recently post-op from cardiac or thoracic surgery will often have limited windows and possibly uninterpretable images no matter how skilled the sonographer. Some of these limitations can be overcome with off axis imaging, use LV contrast or with transesophageal imaging if needed.
- PLAX Main Page
- PLAX: RV inflow view
- PLAX: PA long axis view
The parasternal long axis view is generally the first view obtained in a routine transthoracic echocardiogram. It is the standard view for making M-mode and 2D measurements of the left ventricle, aortic root and left atrium. The patient is best imaged lying on their left side, with their left arm under their head.
|Transducer Position: The transducer is placed 2-3 inches to the left of the sternum in the 4th or 5th rib interspace. The notch on the transducer should be facing towards the 10 o’clock position toward the right shoulder. From this position, the standard view can be obtained. By manipulating the tip of the transducer, the RV inflow view and PA long axis view can also be obtained as shown on the additional tabs above.|
| If the heart is viewed anteriorly, this is how it would appear to lie in the chest. The light blue trapezoid demonstrates how the ultrasound beam slices through the heart to obtain a 2D image.
||As one can see, the most anterior structure is the right ventricular outflow tract here, just below the PA and in the far field we have the left ventricle, left atrium and descending aorta.|
Standard Parasternal Long Axis View
In the appropriate standard view shown above, the apex should not be visible. The left ventricle should be oriented almost horizontally. The right ventricular outflow tract, left ventricular anteroseptum and inferolateral wall are visualized here as shown above with other key structures labeled. Note the RVOT is seen, and not the right ventricle. Posterior to the left atrium one can sometimes see the proximal descending thoracic aorta. RVOT – right ventricular outflow tract, AML - anterior mitral valve leaflet, PML - posterior mitral valve leaflet, LA - left atrium, LV – left ventricle, AV – aortic valve, and DA - descending aorta.
Zoomed in View of Aortic and Mitral Valve
Similarly zooming in on specific structures such as the aortic valve and mitral valve allows for better visualization of leaflet structures. Typically the right and non coronary cusps of the aortic valve are seen here, however with off-axis imaging, the left coronary cusp may also be seen. RCC - right coronary cusp, NCC - non coronary cusp, AML - anterior mitral valve leaflet.
Ascending Aorta View
By moving the transducer up an interspace, one can see the proximal ascending aorta. This is useful in those who have dilated or calcified aorta root and enlarged ascending aorta.
The parasternal long axis view is used to make a standardized set of measurements. We use both M mode and 2D to make these measurements.
M-mode scans one line across time. These measurements are thus very dependent upon lining up your M-mode correctly with the LV. The convention for all M- mode measurements is to measure from leading edge to leading edge. That is, the measurement starts at the top (or leading edge) of the line that makes up a structure and goes to the top of the next line where the measurement ends. Looks closely at the two measurements below for some examples.
Aortic Root Measurement LA diameter measurement
|For the aortic root and LA measurements, place the cursor over the coaptation zone of the aortic valve cusps. Identify diastole using the start of the QRS on the EKG tracing, right before the aortic valve opens and measure the aortic root size.||Find peak systole with the largest dimension of the left atrium and measure leading edge to leading edge to obtain the LA diameter as shown above.|
Ideally the M-mode cursor for LV measurements should be perpendicular to the LV septum. Otherwise LV dimensions can sometimes be overestimated when off axis. Try to measure the septum and posterior wall thickness at diastole (largest cavity size) which is usually right at the QRS onset and then measure these at systole (smallest LV cavity size). In addition measure the internal cavity dimension. In the M-mode below, the LV diastolic measurement is 4.7cm and the systolic measurement is 2.8cm, both of which are normal.
Because of issues with difficulty in proper alignment with the M-mode cursor, the majority of measurements are now made with 2D imaging. Choose the best diastolic frame with the largest LV cavity (as shown below on the left) and measure the septal and posterior wall thickness as well as the LV diastolic cavity. This is also the appropriate frame in which to measure the aortic root diameter. Then chose a systolic frame (as shown below on the right) to measure LV dimensions as well as the left atrial diameter. With 2 D measurements the blood/tissue interface can be seen using modern equipment and a trailing edge to trailing edge measurement is appropriate.
Because there maybe discrepancies between M-mode and 2D measurements given that M-mode measurements may be off axis or in a different position, large differences should be reconciled before reporting to avoid confusion.
The RV inflow view is obtained by tilting the head of the transducer down and to the left without moving the probe off the chest from the main parasternal long axis position.
MB - moderator band, CS - coronary sinus, RA - right atrium, PL - posterior leaflet, AL - anterior leaflet, RV - right ventricle, IVC - inferior vena cava
In this view, the right atrium, right ventricle, tricuspid valve and sometimes the IVC can be seen. A proper inflow view shows only the RV and not the LV. This in the only transthoracic view which shows the posterior leaflet of the tricuspid valve. If part of the LV is seen, it is not a pure RV inflow view and instead of the posterior leaflet you will be seeing the septal leaflet. The view is otherwise useful for evaluating tricuspid regurgitation and assessing RV inflow and outflow paradox, particularly if apical views are limited in cardiac tamponade. RV - right ventricle, RA - right atrium, TV - tricuspid valve, EV - eustachian valve, SVC - superior vena cava (coming out of the page toward you), IVC - inferior vena cava.
Doppler of the Tricuspid Valve
Color Doppler is typically used to first assess for any evidence of tricuspid regurgitation. This individual below, for example has trace tricuspid regurgitation. Note the inflow (red-orange color) from the IVC.
Thereafter spectral Doppler is used: pulsed wave (PW) Doppler above (right) and below (left) the tricuspid valve in this view.
This is followed by continuous wave (CW) Doppler to measure the tricuspid regurgitation (TR) gradient which is indirectly used to calculate PA pressure. Position the cursor over the area where the TR jet is easiest to see.
|CW Doppler can be used to calculate the pressure gradient across the tricuspid valve when there is TR to estimate the PA systolic pressure (because it is equal to the RV systolic pressure in most people) when there is no significant pulmonic stenosis. Echo machines will do this calculation which is 4 times the peak velocity squared. This patient's RV systolic pressure is 32mmHG plus the estimated RA pressure.|
By tilting the head of the transducer up from the normal parasternal long axis position, the pulmonary artery and pulmonic valve can usually be seen in long axis. This view is useful for evaluating pulmonic stenosis and insufficiency, and for estimating cardiac output through the lungs. It is the best view to see the pulmonic valve, however, the PA bifurcation is rarely seen from the long axis view.
This is how the view looks in real time:
Additional evaluation with color Doppler is usually performed in this view. It is quite common to see trace or mild pulmonic regurgitation as shown below in diastole (left picture) with the red color jet.
Next use pulsed wave Doppler above and below the valve assess whether there is evidence of pulmonic stenosis. As shown below the peak velocity above (right) and below (left) the valve are similar, suggesting there is no stenosis. There is also nice laminar flow as outlined by the pulsed wave Doppler jet.
Continuous Wave Doppler of the Pulmonic Valve
|CW Doppler of the pulmonic valve is useful if you see high flow velocities or to calculate a PA diastolic pressure if you see some pulmonic regurgitation In this case the systolic velocity flow (below the baseline envelope) and diastolic regurgitation jet (above the baseline envelope) are seen and can be evaluated. The velocity at the end of the pulmonary regurgitation jet (at end diastole) can be used to estimate the PA diastolic pressure after adding the RA pressure. Just use 4 x peak velocity squared + RA pressure. Here the end diastolic velocity is about 1m/s.|
This position encompasses several different views of the LV in short axis that differ in how basal or apical the probe is. The most basal window lays out the aortic valve, pulmonic valve, and tricuspid valve. Other standard views include the LV at the mitral valve level, the mid ventricle level and apex all shown sequentially below.
Transducer position: To obtain the short axis view, turn the probe clockwise until you are almost perpendicular to the long axis plane. Typically the probe marker is now oriented at 2 o’clock (toward the patient's left shoulder). From here, tilting probe handle up and down allows one to scan up and down the ventricle to obtain apical and basal views. In those with large hearts moving the probe up and down and interspace may be needed.
The figure below shows the different parasternal short axis views obtained just by tiling the probe from base to apex. It is important to obtain all the views shown below in order to assess 16 of the 17 different segments of the left ventricle (note that the 17th segment, the apex, can only be seen from an apical window). Each view is discussed in more detail below with the corresponding live echo video.
RVOT - right ventricular outflow tract, PV - pulmonic valve, TV - tricuspid valve, PA - pulmonary artery, RA - right atrium, LA - left atrium, AV - aortic valve, AML - anterior mitral leaflet, PML - posterior mitral leaflet, ALPM - anterolateral papillary muscle, PMPM - posteromedial papillary muscle, RV - right ventricle, LV - left ventricle.
Short Axis: Aortic, Tricuspid and Pulmonic Valve Level
This is the most basal short axis view that lays out the 2 atria, 3 valves and the RV outflow tract. Repeat PW and CW across the tricuspid valve is usually done here. TV - tricuspid valve, RA - right atrium, LA - left atrium, AV - aortic valve, PV - pulmonary valve, RVOT - right ventricular outflow tract, PA - pulmonary artery.
Short Axis: Zoom in on the Aortic Valve
It is quite useful to zoom in on the aortic valve to try to assess whether it is trileaflet. Color Doppler here can also help tell the origin of a regurgitant jet. The cusps can always be identified as follows, whether in this view, the subcostal view or via TEE: the intra-atrial septum always intersects the non coronary cusp; the right coronary cusp is the most anterior and abuts the right ventricular outflow tract. The left coronary cusp is therefore the one that is left. Sometimes slight angulation will allow visualization of the left main and right coronary arteries. RCC - right coronary cusp, LCC - left coronary cusp, NCC - non coronary cusp.
Pulmonary Artery View
Slight angulation superiorly will show the pulmonary artery and sometimes past the bifurcation. This is the view that is useful for seeing a PDA with color Doppler (usually a jet seen along the left PA). Also note the geometry of the pulmonary valve and artery, more anterior and almost perpendicular to the aortic valve plane. It is important to use PW Doppler above and below the pulmonic valve. Sometimes PW Doppler can be done separately in each pulmonary artery branch if stenosis or a mass is seen. Note that this individual is in atrial flutter during the echocardiogram. PA - pulmonary artery, PV - pulmonic valve.
Short Axis: Mitral Valve Level
Tilting the probe tip downward the view of the base of the LV and mitral valve can be seen. The ventricle in this view should be round and not oval when done properly. In this view and the next two, many of the 17 different segments of the LV wall can be assessed individually. Note it is the RV insertion site anteriorly which separates septum from anterior wall and the RV insertion site inferiorly which separates septum from the inferior wall. Simply assuming the the 12 o’clock position on the LV identifies the anterior wall will not always be correct, especially in hearts that are rotated. AML - anterior mitral leaflet, PML - posterior mitral leaflet
Short Axis: Mid Ventricle Level
The mid ventricle level is identified by the presence of the two papillary muscles, which should not be confused for masses or thrombi. ALPM - anterolateral papillary muscle. PMPM - posteromedial papillary muscle.
Short Axis: Left Ventricular Apex
Tilting the probe even more inferiorly allows one to see the very apical segment which has no clear papillary muscle structures.
- Apical Main Page
- Apical 4 Chamber
- Apical 5 Chamber
- Apical 2 Chamber
- Apical Long Axis
The apical views are obtained by placing the probe at the point of maximal impulse. There are numerous views that are obtained from this position including the 4 chamber view , the 5 chamber view which includes the LV outflow tract, the 2 chamber view and the apical long axis view (sometimes called the 3 chamber view) all by rotation and minor manipulation of the probe.
The apical windows are the most useful for:
1) Assessing flow across the aortic, tricuspid and mitral valves with Doppler as flow across them is parallel to the direction of the ultrasound beam. This information can be used directly to assess for degree of stenosis and regurgitation as well as respiratory inflow paradox across the valves which is sometimes seen in cardiac tamponade and constriction.
2) Assessment of diastolic function, including use of tissue Doppler and pulsing across the pulmonary veins, up to 3 of which may be visible in this position.
3) Assessment of RV size and function including use of tricuspid annular plane systolic excursion (TAPSE)
4) Evaluation of LV segmental wall motion and evaluation of LV thrombus (the apex is in the near field), sometimes with help of an IV echo contrast agent.
5) Assessment for a PFO or ASD in conjunction with the use of saline contrast.
Click on the links above or from the menu tab to learn more about each view.
|Transducer position: The apical views are obtained by placing the transducer at the point of maximal impulse. The 4 chamber view is usually obtained first with the probe indicator at 3 o’clock (toward the patients left side).|
Standard 4 Chamber View
|The probe slices through the apex, and right and left ventricles in this view. The atria are in the far field.||
The field cut of view is such that the aortic root and aortic valve are not seen in this plane.
RV - right ventricle, LV - left ventricle, DA - descending aorta, TV - tricuspid valve, MV - mitral valve, RA - right atrium, LA - left atrium
The actual live echo window looks like this:
In the standard 4 chamber, all four major chambers of the heart can be seen as shown above. The LV lateral wall, apex and septum are typically laid out. In the appropriate orientation, the septum lines up vertically near the center of the screen. The LV and LV apex should be vertically oriented and the LV should be parabolic in shape as shown. If the LV apex appears round or is off center in only this view and not others then you are likely "off axis" which can affect interpretation. This view is also used to assess RV size and function, atrial size, abnormal intra-atrial and interventricular septal movement, as well as diastolic function. A few institutions have standardized this view in right-left reverse with the left ventricle on the left side of the screen and the right ventricle on the right of the screen. The majority of hospitals otherwise use the convention we show above. LV - left ventricle, RV - right ventricle, LA - left atrium, RA - right atrium, TV - tricuspid valve, and MV - mitral valve.
the septum should be oriented vertically in the center of the screen and the LV and LV apex should be vertically oriented and parallel to the direction of the sound beams.
Zoomed in view of the Left Ventricle
It is important attempt to get a good look at all of the walls of the left ventricle. In this view the inferoseptum, lateral wall and apex can be seen. The lateral wall is usually the least well seen here because the wall itself is parallel with the ultrasound beam.
In addition to LV function assessment, below are some examples of what additional information can be gathered in this view. In the apical 4 chamber view it is important to use color Doppler to assess the mitral valve, the tricuspid valve and the pulmonary veins. Spectral Doppler should also be used to assess for the filling pattern of both valve, and to help quantify regurgitation as well as diastolic function. Tissue Doppler is frequently used at the lateral and septal mitral annulus to help assess diastolic function as well. This is discussed further in the diastolic function section.
Assessment of valvular regurgitation
Use of color Doppler below shows the presence of tricuspid valve (left) and mitral valve (right) regurgitation. Quantification of mitral regurgitation requires use of spectral Doppler and is discussed elsewhere.
Assessment of diastolic function
This involves a combination of assessment of mitral valve inflow, pulmonary vein flow and tissue Doppler Normal examples are shown below. Diastolic function is covered in more detail in another section.
Normal Mitral Valve Inflow Pattern
The E wave represents early passing filling and the a wave represents atrial contraction. Under normal circumstances the E wave is larger than the a wave and the deceleration time is not markedly prolonged or shortened.
Normal tissue Doppler of the septal (left) and lateral (right) mitral annulus.
The E' and A' waves res present the same parts of the cardiac cycle as above, but the ' denotes that we are talking about tissue velocity movements and not blood flow. Note that the velocity of tissue is much lower than blood. The peak E' velocity if about 15cm/s, whereas the peak E wave velocity using PW Doppler above was about 80 cm/sec. Normally the peak E' velocities are 10 cm/s and 15 cm/s at the septal and lateral mitral annulus, respectively. This pictures above therefore show normal tissue Doppler velocities.
Normal pulmonary vein color Doppler and inflow pattern.
Normal pulmonary vein flow pattern has 3 main components, an S wave that represents systole, a D wave that represents diastole and an A wave that represents reversal of flow during atrial contraction. Normally the S wave is larger than the D. Other nuances of pulmonary vein flow are covered elsewhere.
Assess right ventricular function
Tricuspid annular planar systolic excursion or TAPSE is another optional measurement that is not common in many protocols, but is worth being familiar with. It is performed in the apical 4 chamber. It is basically M-mode assessment of RV function where the M mode cursor is placed through the TV lateral wall annulus. The distance of excursion in systole (how much the annulus moves toward the probe) is measured. In the above view a diagonal tracing is made from base to peak and the VERTICAL distance is what is measured in the M mode. A normal TAPSE value is greater than 2 cm, which in the video above on the left represents the vertical distance the annulus travels from base to apex in systole. Additional measures of RV function, such as the fractional area change, can also be calculated from the four chamber view, if desired.
By tilting the head of the probe upwards you move to more anterior structures and create the apical 5 chamber position, the LVOT, aortic valve and proximal aorta can be seen. It is called the 5 chamber view because the ascending aorta is now also seen in addition to the two ventricles and two atria.
Note that with the probe tilted anteriorly the ultrasound beam place slices through the aortic valve and aortic root.
AV - aortic valve, RV - right ventricle, LV - left ventricle, RA - right atrium, LA - left atrium, MV - mitral valve, TV - tricuspid valve.
The live echo view is shown below:
This is a useful view for evaluating aortic stenosis and regurgitation, and allows Doppler assessment of gradients across the aortic valve in aortic stenosis and measurement of deceleration slopes in aortic regurgitation. It is also good for the evaluation of the LVOT gradient as seen in cases of hypertrophic cardiomyopathy for example. Given that angulation is more anterior, the portion of the septum now visualized in this view is the anteroseptum. Ao - aortic root, RV - right ventricle, LV - left ventricle, RA - right atrium, LA - left atrium.
Aortic Valve Assessment
To better assess the aortic valve and for the presence of stenosis and regurgitation, color Doppler and spectral Doppler are used.
Color Doppler across the aortic valve
It is important to assess for aliasing flow as there may be flow acceleration in the LVOT. When seen, aortic regurgitation is commonly overestimated in this view and hence it is not typically used in quantification assessment. The quantification of aortic regurgitation and stenosis are discussed elsewhere. The above video shown normal color Doppler profile across the aortic valve.
Spectral Doppler of the Aortic Valve
Pulse wave Doppler at the LVOT (left picture) usually gives a peak velocity near 1 meter/second in most individuals. Above the aortic valve (right picture) if there is a significant increase in this peak velocity (usually over 2 meters/second) then this suggests possible aortic stenosis. Pulse wave Doppler usually will alias at this velocity and continuous wave Doppler is needed to get the peak velocity. Note that the PW above the valve the velocity is similar to that in the LVOT.
CW Doppler is now used, showing a similar peak velocity profile along the LVOT and across the aortic valve as seen with PW Doppler There is no evidence aortic stenosis. If one were to measure peak and mean gradients are shown here, they are nominal.
Transducer Position: By rotating the probe approximately 90 degrees counter clockwise from the apical 4 chamber position, the apical 2 chamber view can be obtained.
|This view bisects the left ventricle, along the anterior and inferior wall.||Sometimes the left atrial appendage can also be seen in this view.|
A Standard 2 Chamber View
This view is excellent for assessing wall motion of the inferior wall, anterior wall and apex. It is another useful view for assessing the mitral valve. Note the descending thoracic aorta can also be visualized in this view if off axis imaging is used whereby the LV will appear more foreshortened, as shown below.
Off Axis Imaging to Bring in the Thoracic Aorta
|Transducer Position: The apical long axis, sometimes called the three chamber view is obtained by rotation of the probe another 90 degrees counter-clockwise from the apical 2 chamber position. The probe is thus facing around 9 to 10 o'clock.|
|Rotating the probe from the two chamber position now bisects the aortic root and aortic valve.||The anteroseptum now comes into view. Compare this view plane to the parasternal long axis. It is virtually the same except the probe is in a different location.|
The live echo view is show below:
This view shows similar structures to the parasternal long axis except now the LV apex is well visualized and is in the near field. The LV wall segments and views of the aortic and mitral valves are the same. Ao - aorta, AV - aortic valve, LA - left atrium, LV - left ventricle, PML - posterior mitral leaflet, AML - anterior mitral leaflet, and RVOT - right ventricular outflow tract.
In this view the color and spectral Doppler of the aortic valve and mitral valve should be performed. The probe may have better alignment with the flow through the LVOT and aortic valve in this view compared to the 5 chamber view. It is important to assess the velocity time profiles in both views.
- Subcostal Long Axis
- Subcostal Short Axis
- Subcostal Great Vessels
Transducer Position: The patient is placed flat on their back. Sometimes it helps for the head to be slightly elevated or if the patient takes in a deep breath. It may also be helpful if the patient bends their legs.
Scan under the subxyphoid process until a standard 4 chamber view is obtained. Increasing the depth is usually needed depending on how high up the heart is located.
The heart is now in the far field, and the ultrasound beam has to go through the liver first, before slicing through the right ventricle and then left ventricle.
The structures seen are roughly similar to the apical four chamber however now the ultrasound beam is more perpendicular to the atrial and ventricular septum.
This view is excellent for looking at the anterior RV free wall, to assess for RV thickness, and for the evaluation of pericardial effusions. It is also one of the most useful views for evaluating flow across the intra-atrial septum for the presence of a PFO or ASD. RV- right ventricle, LV - left ventricle, LA - left atrium, RA - right atrium, TV - tricuspid valve, and MV - mitral valve.
|This is also a good view to assess for an atrial septal defects or patent foramen ovale as the color Doppler window is now perpendicular to the intra-atrial septum.||
Color Doppler across the intra-atrial septum
View of the SVC from the Subcostal Window
|On occasion, from the 4 chamber view the SVC can be seen with some additional angulation toward the head. It is shown here as a color flow toward moving upward on this image into the right atrium.|
Short Axis View from the Subcostal Position*
If the probe is rotated counterclockwise from the long axis position then short axis images of the LV, valves be obtained. Some fine tuning with tilting the head of the probe may also be needed depending on the orientation of the heart in the chest. Views in this plane very similar to the parasternal short axis views, however the heart ultrasound beam is now coming from an inferior direction.
*Note that these views are useful to attempt in those who have poor parasternal windows in order to get the valves and left ventricle in short axis. One does not necessarily need these views if the parasternal short axis images are of high quality.
TV - tricuspid valve, RVOT - right ventricular outflow tract, PV - pulmonic valve, PA - pulmonic artery, LA - left atrium, RA - right atrium, RV - right ventricle, AML - anterior mitral leaflet,
PML - posterior mitral leaflet, LV - left ventricle, ALPM - anterolateral papillary muscle. PMPM - posteromedial papillary muscle.
Two live views are shown below:
On the right above is shown the LV at the papillary muscle level. On the left is shown the aortic valve (center), tricuspid valve (top) and pulmonic valve level (just to the right of the aortic valve). You can be sure these are subcostal views because the liver is clearly visible.
|Transducer Position: Rotate the probe 90 degrees
counter clockwise from the 4 chamber subcostal view
so that the probe is pointing toward the head at
12'o'clock. Tilting medially and laterally will help
show the IVC and aorta
Abdominal Aorta: Color Doppler
The abdominal aorta can be found by tilting the probe medially until this pulsatile thick-walled structure is seen. This view assesses the abdominal aorta from which the celiac artery can sometimes be seen to arise. PW can be performed here although blood flow may sometimes be quite perpendicular to the transducer.
Subcostal View of the IVC
To get this view, tilt the probe more right lateral from the abdominal aorta view. Alternatively from the subcostal four chamber, visualize the right atrium and turn the probe from the 9 o'clock position to the 12 o'clock position. This view is used to assess RA pressures based on inspiratory collapse of the IVC. Lack of collapse suggests high RA pressures where as complete collapse suggests low RA pressures. Note the change here in IVC diameter with respiration. Sometimes an M mode through the IVC as shown above on the right can better help show respiratory changes with time. This topic is covered further in the hemodynamics section.
Color Doppler of the Middle Hepatic Vein
Slight angulation around the IVC position will show the middle hepatic vein, shown above with color Doppler PW can then be done to reveal the characteristic waveform which gives information about right sided pressures and hemodynamics as there is no valve between the middle hepatic vein and the right atrium. Shown are the A wave (atrial contraction), S wave (systole) and D wave (diastole). Reversal of the S wave may be seen with significant tricuspid regurgitation.
- Suprasternal Long Axis
- Suprasternal Short Axis
- SVC view
|Transducer Position: Have the patient lie completely flat without anything under the head. Ask them to lift their chin upward and look to the left. Then place the transducer in the suprasternal notch with the probe pointed at the left shoulder at about 2 o'clock. Sometimes you may need to tilt the probe to point downward.|
Note that in this view the right pulmonary artery courses underneath the arch, therefore we see it in a short axis view here.
It is often difficult to see all 3 major branches from the aortic arch. The descending aorta is also less well seen in the far field in this view.
A an example of a live echo view is shown below
This view usually gives a nice look at the arch, from which the 3 major vessels may be seen to arise. The right pulmonary artery and brachiocephalic vein which empties into the SVC can also be seen. It is important to use color Doppler to assess flow in the ascending and descending aorta and then to use spectral Doppler as shown below.
Pulse wave Doppler in the ascending (right) and descending (left) aorta.
If there is an increase in the velocity of flow in the descending aorta (greater than 1.5 m/s) accompanied by flow turbulence on color Doppler imaging, then this may suggest the presence of aortic coarctation. CW Doppler should be used to assess for the maximal gradient.
Suprasternal Short axis
Transducer Position:Turn the probe clockwise to the 5 o'clock position, roughly perpendicular to the long axis view.
Now the probe is turned 90 degrees the aorta is cut in the short axis plane and the right pulmonary artery underneath is now shown in the long axis. Often the SVC is also bisected here.
In the far field, sometimes the left atrium can be seen, with all four pulmonary veins, the only TTE view in which all 4 veins may be seen.
The live echo view is show below:
Here the aorta is seen in in short axis and the right PA now in long axis. Sometimes in the far field the 4 pulmonary veins can be seen entering the left atrium.
|Transducer Position: Place the probe near the base of the right sternocleidomastoid muscle with the tip at about 11 o'clock.|
This is a challenging view to obtain in many individuals, and sometimes color Doppler is needed to direct you to the SVC. Flow should be blue, away from the probe since this is a venous structure going toward the heart.
Pulsed wave Doppler will show a classic pattern seen in JVP with an A wave, and X and Y descent. There is normally some variation with respiration.
It has become common practice in many echocardiography labs to report LV mass and volumes indexed to body size as well as atrial volumes and these provide more informative data than just standard LV dimensions. Measurements need to be performed with adequate apical and short axis views which are not distorted or foreshortened.
|4 chamber view diastole||4 chamber view systole|
|2 chamber view diastole||2 chamber view systole|
The 4 and 2 chamber views are used to trace out the LV cavity in end systole and end diastole. Use simpson's method of disks, End diastolic and end systolic volumes are calculated which are then used to derive the EF (here shows as EF Biplace=65%). One should not inlude the papillary muscles and make sure to trace all the way out to the true apex. The volumes are then indexed by body surface area.
|Parasternal short axis, mid ventricle, diastole||4 chamber view diastole|
There are two major methods to use 2 D measurements to calculate LV mass: the truncated ellipse (TE) method and the area length method. One needs needs endocardial and epicardial areas from the short axis view at the level of the mid ventricle at end diastole and also the length at the apical 4 chamber view in end diastole (shown as 9.0cm above). Again it is important to not include the papillary muscles.
|4 Chamber view systole||2 chamber view systole|
Atrial measurements are done in peak systole in the 4 and 2 chamber views. Make sure not to trace into the pulmonary veins or to include the left atrial appendage. The volume is also inddexed to body surface area.
A1 and A2 are the two areas measured above. L is the shorter of the 2 lenghts measured above in the 4 and 2 chamber views from the mitral valve to the most superior portion of the left atrium.