Focused Canine Cardiac Ultrasound

Question 1

On parasternal long-axis view, how much bigger should the lumen of the LV be compared to the RV?

Answer 1

3-4 times larger

should be shaped like a bullet with parallel walls and rounded apex

Question 2

In what view do you assess systolic function, what is the normal fractional shorting and how do you calculate it?

Answer 2

parasternal short axis, mushroom view
change in size of LV between maximum diastole and systole

normal fractional shortening 25-45%

FS = [(LVEDD - LVESD) / LVEDD] x 100

Question 3

In what setting would a patient with L-CHF not show LA enlargement?

Answer 3

peracute chordae tendineae rupture

Question 4

What is the typical fractional shortning in dogs with L-CHF from DCM?

Answer 4

FS < 20%

Question 5

What CVC:Ao ratio and CVC collapsibility are >90% sensitive and specific for R-CHF?

Answer 5

CVC:Ao > 0.63
CVC collapsibility < 30%

Question 6

Name 4 differentials fopr R-CHF in dogs

Answer 6

• pulmonary hypertension
• congenital heart disease (pulmonic stenosis and tricuspid valve dysplasia)
• myxomatous (degenerative) tricuspid valve disease
• neoplasia

Question 7

List focused cardiac ultrasound findings indicative of pulmonary arterial hypertension

Answer 7

• RV thickening (concentratic) and enlargement (eccentric) - RV wall thickness similar or > LV - on right parasternal short- and long-axis views
• LV appears small and volume underloaded
• IVS flattening from RV pressure overload - on right parasternal short-axis view (flattened top of mushroom)
• PA diameter larger than Ao on right parasternal short-axis heart base view
• if color and spectral Doppler available: estimated PA pressure on tricuspid regurgitation velocity > 4 m/s

Question 8

List 3 differentials for Pulmonary Arterial Hypertension

Answer 8

• heartworm disease
• chronic bronchopulmonary disease (e.g., dynamic airway disease/obstruction, chronic bronchitis, pulmonary fibrosis)
• pulmonary thromboembolic disease

Question 9

List 5 differentials for cardiac neoplasia leading to pericardial effusion in dogs

Answer 9

• HSA (large breed dogs)
• chemodectomas (brachycephalic dogs)
• mesothelioma
• lymphoma
• metastatic carcinoma

Question 10

What are the criteria of a CVC on focused cardiac ultrasound in a fluid-responsive patient?

Answer 10

collapsibility during respiration > 30%
often difficult to find and smaller in these patients