APEX Cardiovascular AP

Question 1

What spreads the wave of depolarization?

Answer 1

Gap junctions

Question 2

How does K affect RMP

Answer 2

Hyper K increases RMP
HypoK decreases RMP

Question 3

How does CA affect THP

Answer 3

HyperCA increases THP
HypoCA decreases THP

Question 4

Phases of ventricular AP

Answer 4

0 na in
1 cl in, k out
2 ca in, k out
3 k out
4 k seeps out, nakatpase

Question 5

What is THP?

Answer 5

Voltage change that is required to achieve depolarization

Question 6

SA and AV AP phases

Answer 6

4 depolarization, na in(i-f), ca in (t type)
0 depolarization CA in (l type)
3 Repolarization- k out

Question 7

Cardiac accelerator fibers

Answer 7

T1-T4

Question 8

CaO2 is what?

Answer 8

Artierial oxygen content
20ml/O2/dL

Question 9

DO2 is what range

Answer 9

Oxygen delivery
1000ml/min

Question 10

VO2 is what

Answer 10

Oxygen consumption
250ml.min

Question 11

cVO2 is what

Answer 11

Venous oxygen content
15ml/dl

Question 12

CaO2 formula

Answer 12

(1.34 x hgb x SaO2) + (PaO2 x 0.003)
about 20m/dl is goal
Oxygen content

Question 13

DO2 formula

Answer 13

CO x 10 x [(1.34 x hgb x SaO2) + PaO2 x 0.003)]
Delivery of oxygen- how much o2 is carried andhow fast its being delivered
reference- 1000ml

Question 14

EO2 reference

Answer 14

reference - 25%

Question 15

VO2 reference

Answer 15

250ml/min

Question 16

cVO2 formula range

Answer 16

(1.34 x hgb x sao2) + (PvO2 x .003)
15ml/dl
NOT PaO2!!!

Question 17

SVR and PVR normal ranges

Answer 17

800-1600
150-250
dynes/sec/cm-5

Question 18

SVR and PVR formula

Answer 18

(map-cvp/co) x 80
(meanPAP-PCWP/CO) x 80

Question 19

Frank starling is associated with what two variables?

Answer 19

Ventricular output (SV)
Ventricular volume (PCWP=LVEDV)

Question 20

Conditions that reduce myocardial compliance

Answer 20

Hypertrophy
Age
Fibrosis
Diastolic HF

Question 21

Atrial kick %, and when is it most important?

Answer 21

20-30%
In high heart rates bc heart doesnt have enough time to fill passively

Question 22

Conditions that impair inotropy

Answer 22

Hyper K (acidosis)
Hypercarbia (acidosis)
Hypoxia / ischemia (Lactate= acidosis) /
Propofol, CCB, volatile anesthetics

Question 23

What increases contractility?

Answer 23

SNS
Catecholamines
Dig
PDE inhibitors

Question 24

How does B1 stimulate contractility?

Answer 24

ATP to cAMP
cAMP increases PKA
More calcium in and made available via l type ca channel, serca 2 pump is sped up, and ryanodine2 receptor causes CICR

Question 25

Most important electrolyte for contractility?

Answer 25

Calcium

Question 26

LV pressure volume loop (square graph chart)

Answer 26

ACAO MOMC Right (isovolumetric contraction) and top (contraction) are systole Left (isovolumetric relaxation) and bottom (ventricular filling) are diastole

Question 27

Myocardial stress is reduced by what 3 factors

Answer 27

Increased thickness (muscle causes less stress) Decreased radius (doesnt have to stretch as much) Decreased Decreased pressure (same as above)

Question 28

EF formula

Answer 28

(Edv-Esv)/EDV or SV/EDV

Question 29

Mild EF dysfunction

Answer 29

41-49%

Question 30

When looking at a cross section from above, what parts of the heart are being fed by what arteries?

Answer 30

R side- Circumflex Middle bottom to half way up septum- LAD Left side, top side, and half way down septum- inferior RCA

Question 31

Where does SA node get its blood from? AV?

Answer 31

RCA in 70% of people AV node in 80% of people

Question 32

Coronary perfusion pressure formula

Answer 32

DBP-LVEDP

Question 33

H1 vs H2 to coronary vessels

Answer 33

Vasoconstricts Vasodilates

Question 34

Aortic pressure vs LCA flow pressure vs RCA flow pressure

Answer 34

A line tracing A line with low peak, unevenly high dicrotic notch/ low systolic pressure, just a mini a line

Question 35

Which myocardial bed is most susceptible to MI?

Answer 35

endocardium, its far down

Question 36

PLC

Answer 36

PLC IP3 CONTRACTION Constriction Think Phenyl

Question 37

PKA

Answer 37

B1 stimulation - cAMP- PKA ativation activation of Ca channels Stimulates release of Ca from SR Facilitation of CA into SR by SERCA2 to speed up the next ca release

Question 38

How does preload effect Myocardial oxygen?

Answer 38

Decreases supply (heart beating too hard now) Increases demand

Question 39

What is wall tension synonymous with?

Answer 39

Preload

Question 40

DO2 formula

Answer 40

(1.34 x hgb x sao2 + [pao2x.003]) x CO x 10 or ci x hgb x 1.34 x sao2

Question 41

NO effect on afterload, NO MOA

Answer 41

Decreases RV afterload by causing a decrease in PVR Activates guanlyl cyclase, synthesize GTP to cGMP, decreases CA inside cell, causes smooth muscle relaxation

Question 42

2 mediators of coronary vessel dilation

Answer 42

Adenosine B2

Question 43

Severe EF dysfunction

Answer 43

<25%

Question 44

SERCA2 pump

Answer 44

Sarco Endoplasmic Reticulum Calcium ATPase pump Resequesters CA, if you speed this up, then you can speed up the following release of more calcium for another contraction

Question 45

How can we influence(increase) SA node AP?

Answer 45

Increase rate of phase 4 via sns decrease THP Increase RMP