Chapter 106: Cardiac Surgery Flashcards
Which coronary artery is dominant in dogs and cats?
Dogs - left
Cats - right**
What is the first branch of the aortic arch?
Second?
1st: Brachiocephalic trunk
2nd: Left subclavian artery
What factors determine stroke volume?
Preload
Afterload
Contractility
What causes a reverse PDA?
Supresystemic pulmonary hypertension
List the components of Tetralogy of Fallot:
- Pulmonic stenosis
- Ventricular septal defect
- Overriding aorta
- Right ventricular hypertrophy
The most common cyanotic heart defect in companion animals
What is cor triatriatum?
What are the two main types?
An uncommon congenital defect resulting in the persistence of an embryonic membrane that causes obstruction of venous flow through the atrium.
- Cor triatriatum dexter - on the right. Chow chows overrepresented
- Cor triatriatum sinister - on the left, reported in cats
In figure 106.6 (the Cardiac ventricular pressure-volume loop graph), what does the inner area of the loop on the graph represent?
Cardiac work
There are two types of cardiac work:
-generation of pressure
-ejection of volume
What is different about the pulmonary and umbilical veins?
They carry oxygenated blood (even though they’re veins)
Afterload is the amount of systolic wall stress (SWS) that the ventricle must overcome before it can eject volume. What is the LaPlace relationship?
SWS = systolic pressure x ventricular radius / ventricular wall thickness
Greater afterload = less stroke volume.
What is the equation for cardiac output?
Cardiac output = stroke volume x heart rate
CO=SVxHR
What is the equation for MAP?
How can you use it to find vascular resistance?
MAP=(cardiac output x vascular resistance) + atrial pressure
MAP= (CO x R) + AP
R = (MAP-AP) / CO
What technique of holding your needle holders is not recommended in cardiac surgery?
Palming - too much risk of motion.
What makes cardiac surgery different than other tissues?
Motion of the heart.
What are pledgets?
Little buttresses that you should have in a variety of sizes in cardiac procedures in case you needed to buttress your stuff.
