Cardiovascular anatomy and physiology 4

Question 1

What are the four phases of the ventricular pressure-volume loop?

Answer 1

period of ventricular filling (bottom horizontal line)
isovolumetric contraction (right vertical line)
ventricular ejection (top horizontal line)
isovolumetric relaxation (left vertical line)

Question 2

_________ is the percentage of how much blood is pumped by the heart during each beat

Answer 2

The ejection fraction

Question 3

The amount of work the ventricle must do to eject its stroke volume is called

Answer 3

the external work

Question 4

The LV’s external work can be estimated by

Answer 4

multiplying the stroke volume (width) by the mean aortic pressure (height)

Question 5

An EF of ___________ indicates severe dysfunction

Answer 5

<25%

Question 6

An EF of ____________ indicates moderate dysfunction

Answer 6

26-40%

Question 7

An EF of __________- indicates mild dysfunction

Answer 7

41-49%

Question 8

An EF of ____________- is normal

Answer 8

> 50%

Question 9

The morphology of the pressure-volume loop is affected by changes in

Answer 9

preload, contractility, and afterload

Question 10

How does an increased preload affect the PV loop?

Answer 10

PV loop gets wider but returns to the original end-systolic volume

Question 11

How does a decreased preload affect the PV loop?

Answer 11

PV loop gets narrower but returns to the original end-systolic volume

Question 12

How does an increased contractility affect the PV loop?

Answer 12

PV loop gets wider, taller, and shifts to the left

Question 13

How does a decreased contractility affect the PV loop?

Answer 13

PV loop gets narrower, shorter, and shifts to the right

Question 14

How does an increased afterload affect the PV loop?

Answer 14

PV loop gets narrower, taller, and shifts the ESV to the right

Question 15

How does a decreased afterload affect the PV loop?

Answer 15

PV loop gets wider, shorter, and shifts the ESV to the left

Question 16

An example of decreased preload would be

Answer 16

furosemide

Question 17

The _____ & _______________ arise from the aortic root

Answer 17

left and right coronary arteries (LCA & RCA)

Question 18

The LCA divides into the

Answer 18

left anterior descending and circumflex arteries

Question 19

The left anterior descending artery perfuses the

Answer 19

anterolateral & apical walls of the left ventricle as well as the anterior two thirds of the interventricular septum

Question 20

The EKG leads that correlate with the left anterior descending artery are

Answer 20

V1-V4

Question 21

The circumflex artery supplies the

Answer 21

left atrium
lateral & posterior walls of the LV

Question 22

The EKG leads that correlate with the circumflex arteries are the

Answer 22

I, aVL, V5-V6

Question 23

The right coronary artery perfuses the

Answer 23

right atrium, right ventricle, interaterial septum and the posterior third of the interventricular septum

Question 24

The EKG leads that correlate with the right coronary artery include

Answer 24

II, III, aVF

Question 25

The posterior descending artery perfuses the

Answer 25

inferior wall

Question 26

Blood returning to the left side of the heart by way of the Thebesian circulation contributes to

Answer 26

a small amount of anatomic shunt

Question 27

When using TEE/TTE, the best view for diagnosing myocardial ischemia is

Answer 27

the midpapillary muscle level in short-axis

Question 28

The coronary sinus resides on the

Answer 28

heart’s posterior surface and it returns cardiac venous blood to the right atrium

Question 29

The origin of the posterior descending artery defines

Answer 29

coronary dominance

Question 30

The SA node receives its blood supply from the _______ in about 70% of patients

Answer 30

RCA

Question 31

The AV node receives its blood supply from the ________ in about 80% of patients

Answer 31

RCA

Question 32

The Bundle of His is perfused by the _______ in about 75% of patients

Answer 32

LCA

Question 33

The left and right bundle branches are almost exclusively supplied by the

Answer 33

LCA

Question 34

What are the three main coronary veins and their corresponding arteries?

Answer 34

great cardiac vein (LAD)
middle cardiac vein (PDA)
anterior cardiac vein (RCA)

Question 35

Most blood returns to the

Answer 35

coronary sinus which can be cannulated to administer retrograde cardioplegia

Question 36

The second best view for diagnosing left ventricular ischemia is the

Answer 36

apical segment also in short axis

Question 37

Mediators of coronary vasodilation include: (select 2)
a. adenosine
b. beta-2 stimulation
c. alpha-1 stimulation
d. hypocapnia

Answer 37

a. adenosine
b. beta-2 stimulation

Question 38

The heart matches its blood flow to

Answer 38

its metabolic needs

Question 39

At rest, the coronary blood flow is

Answer 39

225-250 mL/min.

Question 40

What is the coronary blood flow equation?

Answer 40

coronary blood flow= Coronary perfusion pressure/coronary vascular resistance

Question 41

What is the coronary perfusion pressure equation?

Answer 41

coronary perfusion pressure= aortic DBP-LVEDP

Question 42

Coronary blood flow autoregulates between a MAP of

Answer 42

60-140 mmHg

Question 43

_________ is the most important determinant of coronary vessel diameter.

Answer 43

Local metabolism

Question 44

Autoregulation of coronary blood flow is the net effect of three things:

Answer 44

local metabolism
the myogenic response
the autonomic nervous system

Question 45

A good example of when the ANS affects coronary vascular tone over that of local metabolism is

Answer 45

patients with prinzmetal angina have overactive coronary alpha receptors that cause intense vasoconstriction and chest pain