Set 2 Flashcards
To visualize the anterior wall of the left ventricle, which two dimensional view would you use?
The anterior and inferior walls of the left ventricle are best visualized in the apical two chamber view
To visualize the anterolateral wall of the left ventricle, which two dimensional view would you use?
The anterolateral wall of the left ventricle is best visualized in the apical four chamber view
(Can also be seen in short axis)
On the electrocardiogram, at what point does the mitral valve normally close?
The mitral valve normally closes approximately 60 milliseconds after the onset of the QRS complex, or about halfway through the QRS complex
On the electrocardiogram, at what point does the aortic valve normally open?
The aortic valve normally opens at the end of the QRS complex.
This takes into account the delay between electrical and mechanical systole, as well as the isovolumic contraction time.
What is the relationship between electrical and mechanical systole?
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 be best appreciated during M-mode studies that examine the relationship between the electrocardiographic pattern and valvular motion
What is diastasis?
Diastasis denotes the middle portion of diastole, which occurs between early rapid filling of the ventricles and the start of atrial contraction. The duration of diastasis varies with heart rate.
Diastasis is quite long in patients with bradycardia and quite short in those with tachycardia
How much of ventricular filling occurs during the passive phase of diastole?
At normal pressures, approximately 70% of ventricular filling occurs during the passive phase of diastole; atrial contraction accounts for the remaining 30% of ventricular filling.
These percentages will change in patients with valvular abnormalities such as mitral stenosis or ventricular compliance problems such as hypertrophic cardiomyopathy.
Name the four phases of diastole
The four phases of diastole are:
- Isovolumic relaxation time (closure of AV to opening of MV)
- Early filling (passive)
- Diastasis
- Atrial contraction (active)
What causes side lobe artifacts?
Side lobe artifacts are caused by strong reflectors outside the main ultrasound beam. These off axis targets create reflections from weaker extra ultrasound beams alongside the main beam
What is the best way to minimize side lobe artifacts?
The best way to minimize side lobe artifacts is to:
Decrease the overall gain
Increase the rejection level (filters out noise to increase image quality)
Or decrease the TGC in the area of strong reflectors (such as the pericardium)
What cardiac lesion is detected by injecting agitated saline contrast material into the right side of the heart?
Saline contrast material is injected to detect atrial shunts.
It may also be used to document abnormal venous return and to detect right sided intracardiac masses
Why does saline contrast material rarely appear on the left side of the heart?
After being injected into a peripheral vein, saline contrast material advances into the right atrium.
The mixed bubbles are too large to pass through the pulmonary bed.
If bubbles are seen in the left atrium and the left ventricle within 3-5 beats after injection, an atrial level communication should be suspected
How is the Valsalva maneuver performed?
The Valsalva maneuver is performed in 2 main phases (strain and release)
Inhaling halfway,
Closing the mouth on the thumb, exhaling forcefully, straining against the closed mouth for about 5-10 seconds then opening the mouth and breathing
How does the Valsalva maneuver affect the heart?
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
What causes jugular venous distention?
Jugular venous distention is caused by an increase in right atrial pressure
Name 4 cardiac problems, which commonly result in jugular venous distention.
Four cardiac problems which commonly result in jugular venous distention are:
- Cardiac tamponade
- Pulmonary hypertension
- Tricuspid stenosis/regurgitation
- Constrictive pericarditis
What is the best cardiac view for evaluating mitral stenosis with continuous or pulsed wave Doppler?
With continuous or pulsed wave Doppler, mitral stenosis is best evaluated from the cardiac apex.
Because the apical views allow the Doppler beam and the mitral stenosis jet to be aligned in parallel fashion, these views yield accurate velocities
What is an important constant to remember for using the mitral pressure half time equation?
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 1 cm square (severe stenosis)
How does inhalation of amyl nitrite affect the circulation?
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
How does respiration affect venous return?
Inspiration will cause an overall increase in venous (right sided) return.
Expiration will cause a decrease in venous return
When performing a two dimensional echocardiographic exam, you notice that the image has very little gray scale. Which controls could you adjust to increase the gray scale?
To increase the gray scale quality, you would change the:
Post processing curve or
Compress/reject control
Also check the monitor controls (brightness and contrast) and make sure that the transmit gain is set properly
You notice that the structures in the far field are very hard to see. Which controls could you adjust in order to see them better?
Increasing the TGC control for the far field will brighten the structures in that area.
Also switching to a lower frequency transducer will help with penetration and increase structures in the far field
In the apical four chamber view, you have trouble differentiating an apical thrombus from an artifact. Name 3 things that can help you differentiate these two entities
Ways of differentiating an apical thrombus from an artifact might include:
- Change the depth settings, because range artifacts may move with changes in depth
- Switch to a higher frequency transducer, preferably one with a short focal zone
- Decrease the transmit gain and time gain compensation (TGC) controls in the near field to minimize wall reverberations
- Turn off tissue harmonics
- Use echo contrast
A 32 year old female presents with atypical chest pain. Her blood pressure is 112/50, height 6’0, and weight 115 lbs. An echo is performed with shows mitral valve prolapse. What is a possible diagnosis for this patient?
From the physical description of this patient and the finding on echo of mitral valve prolapse, she may have Marfan Syndrome
Which additional cardiac structures should be evaluated in Marfan Syndrome?
In addition to mitral valve prolapse, the aortic valve and aorta should be evaluated for the presence of valvular regurgitation, aortic dilatation, and possible dissection
How do you obtain an apical two chamber from an apical four chamber view?
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.
What is the easiest way to adjust the color Doppler gain?
With color flow Doppler turned on, increase the color gain until background Doppler noise appears on the color display. Then decrease the color gain until the background noise disappears. Normal and abnormal flow should now be displayed in an optimal manner, if the Doppler display still appears weak, switch to a lower frequency transducer, decrease the depth of field, or narrow the color sector to increase the frame rate
Describe the normal mitral valve anatomy
The mitral valve is a bileaflet valve situated between the left atrium and the left ventricle. The valves anterior leaflet is relatively long, lies close to the aorta, and comprises less of the valves circumference than the posterior leaflet.
The posterior leaflet is shorter, takes up more of the circumference and is usually divided into 3 sections (scallops)
Both the anterior and posterior leaflets are attached to the ventricular papillary muscles by multiple chordae tendinae
Name the 4 classic M-mode findings associated with mitral stenosis
The classic M-mode findings associated with mitral stenosis are:
- Decreased E-F slope
- Decreased “E” wave amplitude
- Multiple reverberant echoes during diastole
- Anterior displacement of the posterior mitral leaflet
Describe the characteristic two dimensional echo findings associated with mitral stenosis
- Left atrial enlargement
- Tethering of the tops of the mitral leaflets
- Thickening of the mitral leaflets, with decreased leaflet mobility
- Pulmonary hypertension and right ventricular and right atrial enlargement (which may be evident in severe mitral stenosis)
What is the normal flow velocity (mean value and range) through the mitral valve, as documented by Doppler imaging in adults and children?
The normal flow velocity through the mitral valve in adults is a mean of 0.9 m/sec with a range of 0.6 to 1.4 m/sec
In children the flow velocity is slightly higher, having a mean of 1.0 m/sec and a range of 0.7 to 1.4 m/sec
Describe the changes seen in the Doppler spectral trace in patients with mitral stenosis
- An increase in flow velocity
- An increase in flow turbulence (as detected by pulse Doppler or color flow)
- A decrease in the rate of drop-off for the early diastolic slope (pressure half time)
How does mitral stenosis affect the left atrium?
Mitral stenosis causes an increase in the left atrial pressure, which results in left atrial enlargement.
Severe mitral stenosis can lead to pulmonary hypertension, right ventricular failure, and right atrial enlargement
Why do patients with mitral stenosis usually develop atrial fibrillation?
When the left atrium becomes dilated, the atrial internodal tracts are damaged resulting in atrial fibrillation.
Such fibrillation causes further atrial enlargement, as well as atrophy of the atrial muscle and may lead to chronic atrial fibrillation
Name 7 typical physical findings associated with mitral stenosis
- Diastolic murmur (rumble)
- An opening snap
- Atrial fibrillation
- Dyspnea on exertion
- Fatigue
- Orthopnea
- Hemoptysis (spitting up blood)
What causes an opening mitral snap?
An opening mitral snap occurs shortly after the second heart sound (which signifies aortic and pulmonic closure).
The snap is caused by the abrupt cessation of leaflet opening in early diastole when the mitral valve is tethered
Associated with mitral stenosis
A 39 year old male with no cardiac history enters the doctors office complaining of flu like symptoms for one week. A previously undocumented systolic murmur is heard. An echo reveals an abnormally thick anterior mitral valve leaflet and mild mitral regurgitation. What is the most likely cause of these echo findings?
With a new murmur and the echo finding of mitral valve thickening in a young person, the most likely diagnosis is mitral valve endocarditis
What additional tests will be helpful in making the diagnosis in a patient with mitral valve endocarditis?
Blood cultures will be helpful in identifying the organism and a TEE will further assess the extent of mitral leaflet thickening
