Cardiovascular Physiology Review

Front 1

What is a major determinant of mortality?

Back 1

the state of the arteries

Front 2

Which vessels determines blood pressure and blood flow?

Back 2

arteriolar resistance arteries

Front 3

What provides electrical isolation between the atria and ventricles?

Back 3

cartilaginous ring in which the mitral and tricuspid valves are attached

Front 4

What provides the electrical connection between the atria and ventricles?

Back 4

AV node

Front 5

Important feature of the AV node that allows times for mechanical filling of ventricles from atria

Back 5

electrical delay

Front 6

EKG: P wave represents?

Back 6

atrial mass depolarization

Front 7

EKG: QRS complex represents?

Back 7

AV node period and ventricular mass depolarizing

Front 8

EKG: T wave represents?

Back 8

repolarization of the ventricle

Front 9

Where is the signal for atria repolarization?

Back 9

low amplitude signal buried within the QRS complex

Front 10

List order of electrical activity in heart.

Back 10

atrial depolarization -> AV node -> His bundle -> bundle branches -> Purkinjie fibers -> ventricular mass depolarization -> ventricular repolarization

Front 11

List three therapies for disorders of the electrical system:

Back 11

mechanical devices (pacemakers), ablation therapy, drug therapy

Front 12

Five factors that regulate CV mechanics:

Back 12

1) preload
2) afterload
3) HR
4) contractility
5) lusitropy

Front 13

Passive load that determines the initial muscle length of the cardiac fibers (sarcomere length) prior to contraction.

Back 13

Pre-load

Front 14

What is a measure of preload in LV?

Back 14

EDV

Front 15

What is the most common cause of CHF?

Back 15

diastolic dysfunction

Front 16

Pressing on the abdomen and looking for distention in the neck veins to test for increased venous pressure

Back 16

Hepatojugular reflux

Front 17

Good representation of filling pressure of LV, relates closely w/ EDP.

Back 17

pulmonary capillary wedge pressure (PCWP), mean pressure of the lungs

Front 18

State Frank-Starling Law.

Back 18

Increased venous return (LV - EDV) leads to increased SV and CO on the next heartbeat.

Front 19

Systolic load against which the heart must contract

Back 19

Afterload

Front 20

Afterload determined by four things:

Back 20

aortic valve, peripheral vascular resistance (of which resistance arterioles are the major determinants, blood properties (mass and viscosity), preload

Front 21

How much tension the heart muscle will develop:

Back 21

contractility

Front 22

What are some conditions which will decrease contractility?

Back 22

fibrosis, hypoxia/ischemia, inadequate myocardial blood flow, certain meds, acidosis

Front 23

Distensibility or diastolic properties:

Back 23

lusitropy

Front 24

Increased LV pressure can lead to what?

Back 24

pulmonary edema -> shortness of breath

Front 25

Major mechanism by which most individuals increase CO in response to increased demand or excercise

Back 25

Increase HR

Front 26

What is a common formula for determining maximum HR?

Back 26

200 - age

Front 27

SV increases in excercise due to what?

Back 27

increased venous return due to skeletal muscle contraction and venous constriction due to SNS

Front 28

How much oxygen is extracted by muscles at rest?

Back 28

95-99% Hb saturation to 75%

Front 29

How much oxygen is extracted by muscles during excercise?

Back 29

95% to 35% Hb saturation

Front 30

What is the problem w/ CHF with respect to oxygen extraction?

Back 30

Decreased CO leads to venous returns with 40% Hb saturation, therefore upon exertion, they have no oxygen in reserve

Front 31

T/F: Myocardial cells are able to enhance oxygen extraction in times of demand.

Back 31

False. Even at rest the myocardium fully extracts oxygen form its available blood supply.

Front 32

T/F: Anerobic metabolism has very limited value for myocardial tissue.

Back 32

True

Front 33

List the 5 mechanisms that are used during time of exertion.

Back 33

increase HR, increase SV, increase oxygen extraction, restribution of blood flow, anaerobic metabolism

Front 34

What are the three effects of sympathetics on the heart?

Back 34

increase HR, contractility, and AV nodal conduction (delay period btwn atria and ventricles has to be reduced)

Front 35

Which dominates in most of our conscious state PS/S?

Back 35

parasympathic (inhibitory)

Front 36

What is the most common arrythmia?

Back 36

atrial fibrillation

Front 37

Left ventricle is not activated in proper sequence or over too long a period of time.

Back 37

Bundle branch block

Front 38

Which vessels determine myocardial blood flow?

Back 38

arterioles in myocardium

Front 39

Four determinants of myocardial oxygen consumption:

Back 39

myocardial mass, wall stress, inotropic state, HR (MAJOR)

Front 40

How does myocardium get more oxygen in times of exertion since it cannot increase its oxygen extraction ability?

Back 40

inrease in coronary blood flow

Front 41

When does the myocardium receive the majority of blood flow systole/diastole? Why?

Back 41

Diastole, b/c myocardium contraction during systole causes constriction of arterioles penetrating myocardium increasing the resistance

Front 42

Coronary blood flow is determined by what pressure gradient?

Back 42

between aorta and LV pressure in diastole

Front 43

What is another determinant of coronary blood flow (beside pressure gradient)?

Back 43

tone of microvascular resistance vessels

Front 44

How much does the diameter of a epicardial coronary vessel have to be decreased b/f causing a significant decrease in coronary blood flow?

Back 44

60-70%

Front 45

What kind of pressure drop is sympomatic when using fractional-flow reserve using a pressure wire?

Back 45

if pressure is 85% or less compare to pressure b/f blockage

Front 46

Why does tachycardia predispose to myocardial ischemia?

Back 46

increases myocardial oxygen consumption and decreases myocardial oxygen supply by shortening diastole

Front 47

Diastole to systole: ____ valve closes.

Back 47

mitral