Focused Cardiac Ultrasound (Doniger)

Question 1

What is the most anterior structure of the heart and thus can be easily identified on US?

Answer 1

Right ventricle

Question 2

What are the 3 point of care questions that can be answered by focused cardiac ultrasound?

Answer 2

1. Is cardiac activity present? Asystole?
2. Is a pericardial effusion present? Are there signs of tamponade?
3. What is the global cardiac function (hyperdynamic, normal, depressed)?

Question 3

What is your choice of transducer for focused cardiac ultrasound?

Answer 3

Low frequency transducer - phased array with a small footprint is the best as it can allow for imaging between the ribs.

Question 4

What are the 4 views for focused cardiac ultrasound?

Answer 4

1. Subxiphoid
2. Parasternal long axis
3. Parasternal short axis
4. Apical four-chamber view

Question 5

What is the most accurate view to identify a pericardial effusion?

Answer 5

Subxiphoid - usually see pericardial effusions at the posterior pericardium where they begin to develop

Question 6

What is the preferred view for assessing left ventricular contractility?

Answer 6

Parasternal long-axis view

Question 7

You attempt a subxiphoid view to assess for pericardial effusion but cannot obtain an adequate image. What is the 2nd best view?

Answer 7

Parasternal long-axis

Question 8

What is the placement of the probe for the parasternal long axis view?

Answer 8

Perpendicular to the chest wall, immediately to the left of the sternum between the 3rd and 4th intercostal space above the level of the nipple line

• indicator should be directed toward’s patient’s right shoulder or 11 o’clock
• Distinguishing feature is that the aortic outflow tract is stacked on top of the left atrium

Question 9

Label the following:

Answer 9

Question 10

What is the best view for evaluation of contractility AND valvular function?

Answer 10

Parasternal short-axis

Question 11

What is the benefit of the following views:

• subxiphoid
• parasternal long
• parasternal short
• apical 4 chamber

Answer 11

Subxiphoid: pericardial effusion

Parasternal long: 2nd view for pericardial effusion and left ventricular contractility

Parasternal short: contractility and valvular function

Question 12

What is the placement of the probe for the parasternal short axis view?

Answer 12

Once you have obtained the parasternal long axis view, rotate the transduce 90 degrees so that the indicator is directed towards the patient’s left shoulder or 1 o’clock position

-distinguishing feature = LV is circular with a valve in the middle resembling a fish mouth (mitral valve) OR can also see the aortic valve at a different level (3 cuspid valve so see Y)

Question 13

Which valve are you seeing here on this parasternal short axis view?

Answer 13

Mitral valve - looks like a fish mouth and you can see the right ventricle to the left of the screen

Question 14

On the parasternal short axis view, which valve is this?

Answer 14

Aortic valve - remember it has 3 leaflets and you see the other ventricles around it

Question 15

What is the placement of the probe for an apical four chamber view?

Answer 15

Could either slide towards the apex of the heart from your parasternal short axis view or find the PMI

• this is usually at 5th IC space next to the nipple
• indicate the probe towards the patient’s left shoulder
• need to rotate the patient onto their left side

Question 16

What is the best way to evaluate for asystole?

Answer 16

While in parasternal long axis view - place cursor over the walls of the left ventricle and put into M-mode to look for contractility

Question 17

What is the main difference between acute vs. chronic pericardial effusions?

Answer 17

In acute pericardial effusions, as little as 150 mL of fluid can cause tamponade given it built up so quickly

In chronic pericardial effusions, since the fluid accumulates over time, there can be a much larger volume of fluid without creating tamponade

Question 18

What effects does a pericardial effusion have on the heart?

Answer 18

1. Increased intrapericardial pressure
2. Progressive limitation of ventricular diastolic filling
3. Reduction of stroke volume and cardiac output

Question 19

What is Beck’s triad?

Answer 19

1. Muffled heart sounds
2. Hypotension
3. Distended neck veins (jugular venous distension)

***Only 30% of patients with tamponade will have all 3 features of the triad and 10% of patients will not have any of them

Question 20

What are the sonographic features of cardiac tamponade?

Answer 20

1. Circumferential pericardial effusion
2. Hyperdynamic heart
3. Right atrial compression during late diastole
4. Right ventricular collapse during early diastole (scalloping)
5. Abnormal MV motion
6. Dilated IVC with lack of inspiratory collapse
7. Swinging heart = counterclockwise rotational movement of the heart = appears late in tamponade

Question 21

How do you perform an ultrasound-guided pericardiocentesis?

Answer 21

Parasternal long-axis view for direct visualization of the needle to decrease complications seen with blind approach (cardiac lacerations, pneumothoraces, pneumoperitoneum, liver lacerations)

Question 22

2 tips to improve scanning in focused cardiac ultrasound?!

Answer 22

1. Use smallest possible footprint especially in small children to facilitate scanning through the ribs
2. Scan as close to the sternum as possible, especially in smaller children and infants