L16: Cardiac Failure, Heart Sounds & Circulatory Shock

Question 1

define cardiac failure

Answer 1

failure of heart to pump enough blood to satisfy needs of the body

Question 2

compensation for acute cardiac failure

Answer 2

–sympathetic stimulation

strengthen contraction
increases tone of vessels = increased mean systemic filling pressure

Question 3

normal CO and right atrial pressure

Answer 3

Co = 5 L/min
rap = 0 mmhg

Question 4

right atrial pressure _____ when the heart experiences damage.

Answer 4

increases

due to retention of fluids - edema

Question 5

ANS mechanisms for acute cardiac failure

Answer 5

baroreceptor, chemoreceptor reflexes and CNS ischemic response

Question 6

during heart failure: blood continues to be pumped _____ the lungs, but it is not …. ?

Answer 6

into

not adequately pumped out of lungs = pulmonary edema

Question 7

2 major problems of left heart failure

Answer 7

1. pulmonary vascular congestion

2. pulmonary edema

Question 8

in _________ , pulmonary _____ can occur so rapidly that it can cause death by suffocation in 20-30 minutes.

Answer 8

severe acute left heart failure

pulmonary edema

Question 9

after moderately severe heart attack: CO and RAP #’s

Answer 9

CO = 2 L/min (5)
RAP = 5 mmhg (0)

Question 10

30 seconds after a moderately severe MI

Answer 10

CO = 4
RAP = 5

after sympathetic activation response

Question 11

one week after a moderately severe MI

Answer 11

CO = 5
RAP = 6

represents a return to normal but have a damaged heart that the sympathetic system is keeping going

Question 12

graphical analysis of decompensated heart disease

Answer 12

progressive shift of venous return curve to right due to continued fluid retention

CO tries to increase to normal but fails and drops back below 1 L/min

RAP is increasing the entire time

Question 13

digitalis function

Answer 13

works on a chronically failing heart

• -by increasing conc. of Ca ions in muscle fibers
• -thus increasing strength of contraction

Question 14

arteriovenous fistula

Answer 14

1. high CO failure
2. overloads heart because of excessive venous return
3. venous return curve, rotates upward

Question 15

Beriberi

Answer 15

1. high CO failure
2. thiamin deficiency
3. decreased blood flow to kidneys causing fluid retention
4. thus increases mean filling pressure
5. venous return curve shifts to right

Question 16

AV fistula results in a major _____ in ______ .

Answer 16

decrease

peripheral vascular resistance

Question 17

beriberi results in a _______ of the heart due to ______ . Which leads to ______ blood flow to kidneys and _______ of fluid.

Answer 17

weakening
lack of thiamine
decreased
retention

Question 18

first heart sound

Answer 18

1. AV valve close at onset of ventricular systole

mitral/tricuspid valves

Question 19

second heart sound

Answer 19

2. semilunar valves close at the end of systole

Question 20

list some valvular defects

Answer 20

1. valvular lesions
2. rheumatic valvular lesions
3. heart murmurs
4. aortic stenosis
5. mitral regurgitation
6. mitral stenosis

Question 21

left to right congenital defects

Answer 21

–blood flows backward and fails to flow thru systemic circulation

Question 22

right to left congenital defects

Answer 22

• -blood flows from right to left side of heart

- -bypassing lungs

Question 23

ductus arteriosus

Answer 23

• -a connection between pulmonary art. and underside of aorta
• -necessary for fetus but bad after birth but takes a few days to shut down

–should just be a fibrous connection in adults

Question 24

patent ductus arteriosus

Answer 24

• -ductus arteriosus never broke down
• -can be surgically tied off
• -unfixed it allows some deoxygenated blood to enter aorta and into systemic circulation

Question 25

tetralogy of fallot

Answer 25

• -mostly due to failure of ventricles to fully separate
• -patent ductus arteriosus
• -aorta shifted to be in between ventricles and not over left

tetralogy refers to four defects occurring at once
3 listed above

Question 26

define circulatory shock

Answer 26

generalized inadequate blood flow thru the body

to the extent that the body tissues are damaged

especially due to too little O2, nutrients delivered to cells

Question 27

list some cardiac abnormalities that decrease ability of heart to pump blood

Answer 27

1. MI
2. toxic state
3. heart valve dysfunction
4. arrhythmias
5. circulatory shock

Question 28

cardiogenic shock

Answer 28

circulatory shock due to diminished cardiac pumping ability

Question 29

list some factors that decrease venous return

Answer 29

1. diminished blood vol.
2. decreased vascular tone
3. obstruction of blood flow

Question 30

what initiates powerful sympathetic reflexes

Answer 30

1. arterial baroreceptors/ stretch receptors
   - –decrease in arterial pressure after hemorrhage
   - –decreases in pressures in pulmonary arteries and veins in thorax

Question 31

3 important effects of sympathetic reflexes

Answer 31

1. arterioles constrict in most of systemic circulation
2. veins and venous reservoirs constrict
3. HR greatly increases

Question 32

factors that cause a person to recover from moderate degrees of shock

Answer 32

1. baroreceptor reflexes
2. CNS ischemic response
3. reverse stress-relaxation of circulatory sys.
4. increased secretion of renin by kidneys
5. increased secretion by post. pituitary gland of vasopressin
6. increased secretion by adrenal medulla of epine.

Question 33

CNS ischemic response

Answer 33

creates more powerful sympathetic stim. thru out body

not activated until arterial pressure is below 50

Question 34

reverse stress-relaxation of circulatory system

Answer 34

causes BVs to contract around diminished blood vol. so that blood vol. that is available fills circulatory sys.

Question 35

vasopressin

Answer 35

ADH

Question 36

recovery from shock by GI

Answer 36

absorption of large volumes of fluid

Question 37

recovery from shock by capillaries

Answer 37

blood capillaries absorb fluids from intercell space

Question 38

recovery from shock by kidneys

Answer 38

conserve water and salt

brain increases thirst and appetite for salt

Question 39

non-progressive shock

Answer 39

sympathetic reflexes and other factors compensate enough to prevent further deterioration of circulation

negative feedback

Question 40

progressive shock

Answer 40

• -positive feedback
• -arterial press. falls low enough that coronary blood flow decreases below required amount
• –heart weakens and decreased CO

Question 41

one of the important features of progressive shock is ?

Answer 41

whether or not it is from hemorrhage

Question 42

neurogenic shock definition

Answer 42

shock occur w/o loss of blood volume

Question 43

neurogenic shock mechanism

Answer 43

vascular capacity increases so much that normal blood amount is not capable of filling circulatory sys.

Question 44

neurogenic shock causes

Answer 44

1. sudden loss of vasomotor tone = massive dilation of veins
2. deep general anesthesia
3. spinal anesthesia
4. brain damage

Question 45

deep general anesthesia

Answer 45

depresses vasomotor center enough to cause vasomotor paralysis

Question 46

spinal anesthesia

Answer 46

blocks sympathetic nervous outflow

Question 47

brain damage

Answer 47

causes vasomotor paralysis