L16: Cardiac Failure, Heart Sounds & Circulatory Shock Flashcards

1
Q

define cardiac failure

A

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

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2
Q

compensation for acute cardiac failure

A

–sympathetic stimulation

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

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3
Q

normal CO and right atrial pressure

A
Co = 5 L/min
rap = 0 mmhg
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4
Q

right atrial pressure _____ when the heart experiences damage.

A

increases

due to retention of fluids - edema

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5
Q

ANS mechanisms for acute cardiac failure

A

baroreceptor, chemoreceptor reflexes and CNS ischemic response

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6
Q

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

A

into

not adequately pumped out of lungs = pulmonary edema

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7
Q

2 major problems of left heart failure

A
  1. pulmonary vascular congestion

2. pulmonary edema

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8
Q

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

A

severe acute left heart failure

pulmonary edema

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9
Q

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

A
CO = 2 L/min (5)
RAP = 5 mmhg (0)
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10
Q

30 seconds after a moderately severe MI

A
CO = 4
RAP = 5

after sympathetic activation response

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11
Q

one week after a moderately severe MI

A
CO = 5
RAP = 6

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

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12
Q

graphical analysis of decompensated heart disease

A

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

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13
Q

digitalis function

A

works on a chronically failing heart

  • -by increasing conc. of Ca ions in muscle fibers
  • -thus increasing strength of contraction
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14
Q

arteriovenous fistula

A
  1. high CO failure
  2. overloads heart because of excessive venous return
  3. venous return curve, rotates upward
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15
Q

Beriberi

A
  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
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16
Q

AV fistula results in a major _____ in ______ .

A

decrease

peripheral vascular resistance

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17
Q

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

A

weakening
lack of thiamine
decreased
retention

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18
Q

first heart sound

A
  1. AV valve close at onset of ventricular systole

mitral/tricuspid valves

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19
Q

second heart sound

A
  1. semilunar valves close at the end of systole
20
Q

list some valvular defects

A
  1. valvular lesions
  2. rheumatic valvular lesions
  3. heart murmurs
  4. aortic stenosis
  5. mitral regurgitation
  6. mitral stenosis
21
Q

left to right congenital defects

A

–blood flows backward and fails to flow thru systemic circulation

22
Q

right to left congenital defects

A
  • -blood flows from right to left side of heart

- -bypassing lungs

23
Q

ductus arteriosus

A
  • -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

24
Q

patent ductus arteriosus

A
  • -ductus arteriosus never broke down
  • -can be surgically tied off
  • -unfixed it allows some deoxygenated blood to enter aorta and into systemic circulation
25
tetralogy of fallot
- -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
26
define circulatory shock
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
27
list some cardiac abnormalities that decrease ability of heart to pump blood
1. MI 2. toxic state 3. heart valve dysfunction 4. arrhythmias 5. circulatory shock
28
cardiogenic shock
circulatory shock due to diminished cardiac pumping ability
29
list some factors that decrease venous return
1. diminished blood vol. 2. decreased vascular tone 3. obstruction of blood flow
30
what initiates powerful sympathetic reflexes
1. arterial baroreceptors/ stretch receptors - --decrease in arterial pressure after hemorrhage - --decreases in pressures in pulmonary arteries and veins in thorax
31
3 important effects of sympathetic reflexes
1. arterioles constrict in most of systemic circulation 2. veins and venous reservoirs constrict 3. HR greatly increases
32
factors that cause a person to recover from moderate degrees of shock
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.
33
CNS ischemic response
creates more powerful sympathetic stim. thru out body not activated until arterial pressure is below 50
34
reverse stress-relaxation of circulatory system
causes BVs to contract around diminished blood vol. so that blood vol. that is available fills circulatory sys.
35
vasopressin
ADH
36
recovery from shock by GI
absorption of large volumes of fluid
37
recovery from shock by capillaries
blood capillaries absorb fluids from intercell space
38
recovery from shock by kidneys
conserve water and salt brain increases thirst and appetite for salt
39
non-progressive shock
sympathetic reflexes and other factors compensate enough to prevent further deterioration of circulation negative feedback
40
progressive shock
- -positive feedback - -arterial press. falls low enough that coronary blood flow decreases below required amount - --heart weakens and decreased CO
41
one of the important features of progressive shock is ?
whether or not it is from hemorrhage
42
neurogenic shock definition
shock occur w/o loss of blood volume
43
neurogenic shock mechanism
vascular capacity increases so much that normal blood amount is not capable of filling circulatory sys.
44
neurogenic shock causes
1. sudden loss of vasomotor tone = massive dilation of veins 2. deep general anesthesia 3. spinal anesthesia 4. brain damage
45
deep general anesthesia
depresses vasomotor center enough to cause vasomotor paralysis
46
spinal anesthesia
blocks sympathetic nervous outflow
47
brain damage
causes vasomotor paralysis