Measurement Techniques, Maneuvers and Sonographic Views

Question 1

Name five technical maneuvers that can differentiate a cardiac mass from an artifact during echocardiography

Answer 1

To differentiate a cardiac mass from an artifact, the examiner can:

• decrease the overall transmit gain and time gain compensation controls
• use multiple cardiac windows (all masses should be documented in two or more echocardiographic views)
• change the depth of view, thereby possibly changing the position of range artifacts
• switch to a higher frequency transducer to improve resolution
• inject contrast material, which may help identify masses by outlining the lesion.

Question 2

When using the Continuity Equation for aortic valve area when should you not use the peak velocities for V1 and V2?

Answer 2

When using the Continuity Equation for aortic valve area and the patient has either a low EF or moderate to severe AI you should use VTI (Velocity Time Integral) not the peak velocities for V1 and V2.

Question 3

What is pulse pressure?

Answer 3

Pulse pressure refers to the difference between the patients systolic and diastolic blood pressures.

Question 4

In what clinical cases might a patient have abnormal pulse pressures?

Answer 4

Patients with aortic stenosis often have a narrow pulse pressure while patients with aortic regurgitation will have a wide (big difference) pulse pressure

Question 5

Name five types of cardiac wall motion that can be seen echocardiograpically

Answer 5

Five types of wall motion are:

1. normal
2. hypercontractile (exaggerated) motion
3. hypocontractile (sluggish) motion
4. akinesia (absence of motion & thickening)
5. dyskinesia (motion opposite to the normal pattern).

Question 6

If you already know the peak tricuspid regurgitation velocity, how can you calculate the right ventricular systolic pressure (RVSP)?

Answer 6

To calculate the RVSP, add the tricuspid regurgitation (TR) gradient (converted from the velocity to mmHg by 4V2) and the estimated right atrial (RA) pressure (from IVC size and collapsibility).

The equation is: RVSP = TR gradient + RA pressure

Question 7

What is the significance of the RVSP calculation?

Answer 7

This calculation is a means of noninvasively calculating the pulmonary artery pressure. In the absence of pulmonic stenosis, the pulmonary artery pressure will be the same as the right ventricular
systolic pressure.

Question 8

How do you assess the right atrial pressure based on the size and collapsibility of the inferior vena cava (IVC)?

Answer 8

Right atrial pressure based on the size and collapsibility of the IVC uses the following criteria based on the 2010 ASE
RV Guidelines.

• 3 mm Hg = normal IVC (< 2cm) & collapses (> 50%)
• 8 mm Hg = intermediate
• 15 mm Hg = dilated (>2cm) & no collapse (< 50%)

Question 9

How would you angle to view the coronary sinus in the apical 4-chamber view?

Answer 9

From the apical 4-chamber view you would angle posterior in order to visualize the coronary sinus, which is located posterior to the mitral annulus.

Question 10

Why is it important to know the location of the coronary sinus and the descending aorta?

Answer 10

The coronary sinus and the descending aorta are important landmarks that can help differentiate pericardial effusions from pleural effusions.

• Pericardial effusions lie posterior to the coronary sinus and anterior to the descending aorta.
• Pleural effusions lie posterior to the descending aorta in the PLAX.

Question 11

What are the normal systolic and diastolic pressures (mean) in the right atrium?

Answer 11

Right atrial pressures (mean) = 6 mmHg

Question 12

What are the normal systolic and diastolic pressures in the right ventricle?

Answer 12

Right ventricular pressures = 25/5 mmHg

Question 13

What are the normal systolic and diastolic pressures in the pulmonary artery?

Answer 13

Pulmonary artery pressures = 25/10 mmHg

Question 14

What are the normal systolic and diastolic pressures (mean) in left atrium?

Answer 14

Left atrial pressures (mean) = 10 mmHg

Question 15

What are the normal systolic and diastolic pressures in the left ventricle?

Answer 15

Left ventricular pressures = 120/7 mmHg

Question 16

What are the normal systolic and diastolic pressures in the aorta?

Answer 16

Aortic Pressures = 120/80 mmHg

Question 17

When is the pressure in the left ventricle at its lowest?

Answer 17

The left ventricle pressure is lowest in early diastole just after the mitral valve opens. After that the left ventricular pressure rises as the chamber fills in diastole.

Question 18

What is the normal mean pulmonary artery wedge pressure?

Answer 18

The normal mean pulmonary artery wedge pressure is 10 mmHg, which equals the left atrial pressure. The PA wedge pressure is NOT the same as the PA pressure.

Question 19

How is the pulmonary artery wedge pressure determined?

Answer 19

A Swan-Ganz catheter is positioned in the pulmonary artery, and a small balloon is inflated at the catheter’s tip.

• The balloon is then floated and wedged into a smaller pulmonary artery.
• A pressure reading is obtained distal to the balloon.
• The inflated balloon prevents the tip of the catheter from sensing the pulmonary pressure, and the left atrial pressure is recorded as it is reflected across the pulmonary bed

Question 20

What happens to the mitral inflow pattern in a normal patient when you have them perform a Valsalva maneuver?

Answer 20

The normal mitral inflow pattern maintains the E/A ratio (E>A) following a Valsalva maneuver but the velocities are lower.

Question 21

To visualize the anterior wall of the left ventricle, which two dimensional view would you use?

Answer 21

The anterior and inferior walls of the left ventricle are best visualized in the apical two-chamber view.

Question 22

To visualize the anterolateral wall of the left ventricle, which two-dimensional view would you use?

Answer 22

The anterolateral wall of the left ventricle is best visualized in the apical four-chamber view.

(The anterolateral wall can also be seen in the short-axis views, but the four-chamber view is best.)

Question 23

On the electrocardiogram, at what point does the mitral valve normally close?

Answer 23

The mitral valve normally closes approximately 60 milliseconds after the onset of the QRS complex, or about halfway through the QRS complex.

Question 24

On the electrocardiogram, at what point does the aortic valve normally open?

Answer 24

The aortic valve normally opens at the end of the QRS complex. This answer takes into account the delay between electrical and mechanical systole, as well as the isovolumic contraction time.

Question 25

What is the relationship between electrical and mechanical systole?

Answer 25

Mechanical systole follows electrical systole by approximately 12 milliseconds. This delay represents the time it takes for the electrical conductive impulse to spread and thereby cause myocardial contraction. The delay can best be appreciated during M-mode studies that examine the relationship between the electrocardiographic pattern and valvular motion.

Question 26

How is the Valsalva maneuver performed?

Answer 26

The Valsalva maneuver is performed in two main phases (strain and release):

• inhaling half-way
• closing the mouth on the thumb, exhaling forcefully, straining against the closed mouth for about 5-10 seconds then opening the mouth and breathing

Question 27

How does the Valsalva maneuver affect the heart?

Answer 27

During the straining phase, the venous return decreases, so that the cardiac output diminishes and a reflex tachycardia occurs. Once the strain is released, the venous return increases, along with right-sided cardiac pressures and the cardiac output; a reflex bradycardia also occurs.

Question 28

What is an important constant to remember for using the mitral pressure half-time equation?

Answer 28

The most important constant (empirical number) to remember for the mitral pressure half-time equation is 220. If the pressure half-time in milliseconds is greater than 220 then the MV area is less than one centimeter square (severe stenosis).

Question 29

How does inhalation of amyl nitrite affect the circulation?

Answer 29

Amyl nitrite is a vasodilator that causes flushing, tachycardia, and hypotension. In general, murmurs associated with aortic or pulmonic stenosis are increased, while those associated with mitral or aortic regurgitation are decreased.

Question 30

How do you obtain an apical two-chamber view from an apical four-chamber view?

Answer 30

From the apical four-chamber view, rotate the transducer approximately 90 degrees counterclockwise, until you see the LV (anterior and inferior walls), mitral valve, and left atrium. If you see the aorta or aortic valve, you have rotated the transducer too far.

Question 31

Which is the most accurate method of calculating the mitral valve area?

• a. using M-mode echocardiography to determine the E-F slope
• b. performing two-dimensional planimetry of the mitral orifice in the short-axis view
• c. using the Doppler pressure half-time

Answer 31

b. Performing two-dimensional planimetry of the mitral orifice in the short-axis view is the most accurate way to measure the mitral orifice, provided that:

• There is no echo dropout
• The beam is perpendicular to the leaflets and is directed at the leaflet tips
• The highest-frequency transducer and the lowest gain settings possible are used.

Note: if the question is which is the EASIER method then the answer is using Doppler pressure half-time

Question 32

What is the normal area of the aortic valve?

Answer 32

The normal area of the aortic valve ranges from 3.0 to 4.0 cm2.

Question 33

What is the normal gradient across the aortic valve during systole?

Answer 33

The normal gradient across the aortic valve during systole is 2 to 4 mmHg in adults.

Question 34

What is the normal aortic valve flow velocity?

Answer 34

The normal aortic valve flow velocity is 1.4 m/sec, with a range of 0.9 to 1.8 m/sec. In children, the normal aortic valve flow velocity is slightly higher, at 1.5 m/sec.

Question 35

Does mitral regurgitation affect the pressure half-time method of calculating the mitral valve area?

Answer 35

Mild-to-moderate mitral regurgitation does not affect the pressure half-time method of calculating the mitral valve area. Whereas the peak mitral flow velocity may increase, the relationship between the peak and the slope remains constant. Severe mitral regurgitation, with large increases in peak mitral flow velocity, may invalidate the pressure half-time method

Question 36

Which of the following methods is the most accurate means of calculating the aortic valve area?

1. M-mode measurement of aortic leaflet separation.
2. Two-dimensional planimetry of the aortic area in the short-axis view.
3. Doppler calculation of the continuity-of-flow equation.

Answer 36

Of these three methods, Doppler calculation of the continuity-of-flow equation (3) is the most accurate means of determining the aortic valve area.

Measurement of aortic leaflet separation does not determine the aortic valve area or indicate what the third aortic leaflet is doing. In most patients, planimetric calculation of the aortic valve area is impossible from the chest wall orientation because of multiple reverberations from the calcified/fibrotic leaflets.

Question 37

How is the pulmonary artery pressure assessed using the Doppler pulmonary artery acceleration time?

Answer 37

The pulmonary artery pressure can be calculated from the pulmonary artery Doppler spectral trace by measuring the systolic acceleration time. The normal systolic acceleration time is greater than 120 msec, as measured from the onset of flow to peak velocity. In patients with pulmonary hypertension, the acceleration time is decreased. In general, an acceleration time of less than 75 msec indicates at least moderate pulmonary hypertension (in adults).

Question 38

What is the normal flow velocity (mean value and range) through the tricuspid valve?

Answer 38

The normal flow velocity through the tricuspid valve is a mean of 0.6 m/sec, with a range of 0.4 to 0.8 m/sec.