Overview of Cardiovascular Disease Flashcards
1
Q
forms of heart disease
A
- myocardial disease
- congenital
- cardiac neoplasia
- valve disease
- pericardial disease
- electrical disease
1
Q
what is the heart’s common response to stress?
A
hypertrophy
2
Q
hypertrophy does NOT equal
A
hyperplasia
3
Q
hyperplasia
A
making more cardiomyocytes
4
Q
hypertrophy
A
increase synthesis of cell components
5
Q
T/F: after birth, cardiocytes continue to multiple up until 1 year of age
A
FALSE- after birth, cardiomyocytes do not multiple
6
Q
forms of hypertrophy
A
concentric, eccentric, mixed
7
Q
T/F: hypertrophy is reversible
A
true
8
Q
concentric hypertrophy
A
response to increased afterload
9
Q
T/F: the number of heart cells you have when you are born is the same amount that you will have when you die
A
true- after birth cardiomyocytes don’t multiple after birth
10
Q
concentric hypertrophy is a response to what
A
increased afterload
11
Q
what is afterload
A
resistance the heart must overcome to pump blood
12
Q
eccentric hypertrophy
A
response to increased preload
13
Q
aortic stenosis and high blood pressure are examples of
A
concentric hypertrophy
14
Q
eccentric hypertrophy is a response to what
A
increased preload
15
Q
preload
A
volume of blood distending heart before contraction
16
Q
a PDA (patent ductus arteriosis) is an example of what hypertrophy?
A
eccentric hypertrophy: there is excess blood returning to the left heart = eccentric
mass of heart is increased in eccentric hypertrophy even though the walls appear thin
17
Q
valve regurgitation, congenital shunts are examples of
A
eccentric hypertrophy
18
Q
in concentric hypertrophy, how are the sarcomeres added
A
in parallel (width)
19
Q
in eccentric hypertrophy, how are the sarcomeres added
A
in series (lengthwise)
20
Q
what is the point of hypertrophy?
A
adding sarcomeres helps to normalize wall stress, lessening the work of the heart
21
Q
long-term, what are consequences of hypertrophy?
A
- blood supply cannot keep up
- muscle becomes ischemic
- results in degeneration, necrosis, replacement fibrosis
22
Q
myocardial necrosis is loss of
A
cardiomyocytes
23
Q
myocardial necrosis occurs due to
A
- ischemia/hypoxia
- catecholamine excess
- oxidative injury
- toxins
- pathogens
24
T/F: once lost, cardiomyocytes are irreplaceable
true
25
ischemic necrosis is related to impaired blood flow of what structures?
coronary blood flow
- coronary narrowing: arteriosclerosis
- coronary thrombosis: heart attach
- impaired coronary flow: hypertrophy, reduced time in diastole, increased wall stress/pressure
- typically worst in subendocardial myocardium: last part to be perfused, under greatest stress
26
coronary narrowing =
arteriosclerosis
27
coronary thrombosis =
heart attack
28
where is ischemic necrosis the most severe? why?
worst in the subendocardial myocardium: it is the last part to be perfused and is under the greatest stress
29
nutritional myocardial necrosis is caused by what? what species does this affect?
vitamin E/selenium deficiency
sheep, cattle, pigs
issues with soil, also related to free radical injury (like toxins)
30
vitamin E/selenium deficiency affects which species
sheep, cattle, pigs
31
causes of toxic myocardial necrosis
- doxorubicin (chemotoxin)
- ionophores (monensin)
- cardiac glycosides (digoxin)
- thallium
- blister beetle
32
myocarditis
inflammation of heart muscle
33
causes of myocarditis
- viral
- bacterial
- protozoal
- auto immune
- response to ischemia
- myocardial disease
34
what are the 2 types of myocardial fibrosis?
1. replacement fibrosis
2. interstitial fibrosis
35
replacement fibrosis
- common response to lost cardiomyocytes
- replacement of muscle with fibrous tissue (scar)
36
interstitial fibrosis
- interstitial deposition of collagen between/around cardiomyocytes
- common in myocardial diseases
37
when looking at a cardiac stain, what color does cardiac muscle stain?
pink
collagen is blue
38
what are consequences of myocardial fibrosis?
- impairs contractile function
- impairs relaxation/filling
- disrupts electrical activity: blocks conduction, causes premature/abnormal activity
- may impact perfusion
39
endomyocardial fibrosis is a form of cardiomyopathy in what species?
cats
40
pathogenesis of endomyocardial fibrosis
- exuberant fibrous tissue spans/obstructs left ventricle
- impairs myocardial relaxation, filling
- results in heart failure
41
what are common myocardial diseases in dogs/cats?
- often genetic/familial origin
- hypertrophic cardiomyopathy
- dilated cardiomyopathy: primary vs secondary
- arrhythmogenic right ventricular cardiomyopathy
- atrial myopathy
- secondary cardiomyopathies
42
what is the most common cardiac disease of cats?
hypertrophic cardiomyopathy!!!
43
what breeds are commonly affected by HCM?
genetic/familial component: maine coon, ragdoll, sphynx
44
pathogenesis of HCM
severe concentric hypertrophy of the L ventricle: results in diastolic dysfunction: impaired filling, reduced compliance
45
HCM is concentric/eccentric hypertrophy
concentric
46
dilated cardiomyopathy
- dilated chambers, poor function
47
what are the types of dilated cardiomyopathy?
1. primary: genetic/familial- doberman pinschers!
2. secondary: taurine deficiency- cats, non-traditional grain free diets- dogs
3. DCM "phenotype": many heart diseases look like DCM at late stages
48
what breeds are predisposed to primary dilated cardiomyopathy?
doberman pinschers
49
what animals can get secondary dilated cardiomyopathy?
cats: taurine deficiency
dogs: non traditional, grain free diets
could also be related to toxins (chemo etc), nutritional, etc
end result of many diseases can look like DCM
50
what type of hypertrophy does dilated cardiomyopathy look like?
eccentric: dilated
pumping ability depressed
51
nutritional cardiomyopathy in dogs
- increased prevalence of DCM-phenotype in atypical breeds
- association with carb sources: lentil, peas, chickpeas, potatoes
52
arrhythmogenic right ventricular cardiomyopathy is common in what breeds?
boxers and bulldogs
53
what is arrhythmogenic rigth ventricular cardiomyopathy
replacement of cardiomyocytes with fat and fibrous tissue, most in RV
- results in abnormal heart rhythms related to islands of abnormal tissue
- can also result in heart failure
54
atrial myopathy
- rare condition: associated with replacement fibrosis thru atria
- loss of atrial electrical activity
- progressive heart failure
- english springer spaniels
55
what breed is commonly affected by atrial myopathy?
english springer spaniels: atria are paper thin and require a pacemaker
56
what systemic disease can cause secondary myocardial changes?
- anemia
- hyperthyroidism
- systemic hypertension
- acromegaly
- diabetes mellitus
- cor pulmonale (lung dz)
- steroid administration (depo)
57
ARVC
arrhythmogenic right ventricular cardiomyopathy
boxers and english bulldogs
loss of cardiomyocytes in the right ventricle and these cells are replaced by fat and fibrous tissue
58
valvular diseases causes
- congenital malformations
- degenerative changes with age (chronic use of valves)
- infection: valvular endocarditis (less common)
59
T/F: atrioventricular valve degeneration is very common in dogs
true
60
degenerative valve disease
1. atrioventricular valve degeneration
- dogs!!
- valve thick, increased chordal laxity
- regurgitation common
2. aortic valve degeneration
- horses!!!
- results in diastolic heart murmur
61
aortic valve degeneration is common in what species?
horses
62
chronic mitral regurgitation increases pressure in which chamber of the heart?
increased left atrial pressure (backflow), goes into pulmonary veins and then lung interstitium
- leakage of high protein fluid (edema) into lung alveoli causes respiratory symptoms
- rarely, left atrial rupture
63
pulmonary valve congenital malformation
leaflets tend to be fused = pulmonary stenosis
64
tricuspid dysplasia
leaflets restricted/tethered: prevents them from closing and causes backflow/regurgitation
65
what heart abnormalities are in dogs/cats/horses (broad)
dogs: valve degeneration
cats: cardiac muscle issue
horses: electrical activity
66
infective endocarditis
- bovine: right sided, other species: left
- large, vegetative growths on affected valves
- yellow (fibrin) and red (hemorrhage) on fresh postmortem species
67
cattle have what sided infective endocarditis?
right sided valves
other species have left valves affected
68
why is treatment of valvular infection difficult?
the fibrin areas surround bacterial colonies, which are isolated little clumps. the valve sits in the center of all of this
69
pericardial disease
fluid accumulation is pathologic
70
fluid accumulation is pathologic, related to:
- heart failure
- tumor bleeding
- infection
- idiopathic
71
what is the most common cardiac neoplasia in cats/
lymphoma
72
what is the most common cardiac neoplasia in dogs
hemagiosarcoma: right auricle!
73
what species do chemodectomas affect?
canines, esp brachycephalics
- heart base (aorta)
74
cardiac neoplasias
1. lymphoma: cats, cattle right atrium
2. hemangiosarcoma: dogs, right auricle
3. chemodectoma: heart base (aorta), canine
4. mesothelioma
75
cardiac shunts
connection between the L and R sides of circulation
76
left to right sided cardiac shunts
- most common shunt
- hole between left and right ventricle: VSD
- allows L ventricular blood to shunt/move over to the right ventricle = causes volume overload
- excessive blood froma rterial side passing to venous side: not getting out to body and just going around and around in chambers
- volume distension
77
rigth to left cardia cshunt
- high pressure
- deoxynated blood to arterial circulation reulting in hypoxemia: will see low O2 signs
78
PDA
patent ductus arteriosis
was part of fetal circulation: alowed blood to by;ass lungs and return to aorta nad back to placenta
if it remains open after birth it causes aortic blood to enter into the pylmonary artery
79
VSD
hole between ventricular chambers
80
atrial septal defect
usually L to R because of higher pressures
hole between atria
81
stages (broad) of heart disease
1. healthy
2. onset of disease (murmur)
3. progressive cardiac enlargement: subclinical, may not show signs
4. onset of clinical disease --> CHF --> death
82
NYHA
new york heart association human assessment - less helpful to us
class 1: asymptomatic, even with exercise
class 2: clinical signs only during strenuous exercise
class 3: clinical signs with routine daily activity
class 4: severe signs at rest
83
ACVIM
stage A: patient at risk for disease
stage B: structural heart disease, no congestive failure (subclinical)
stage C: past or current CHF
stage D: CHF refractory to standard therapy
84
a predisposed heart disease patient is in what stage
stage A
85
a subclinical heart disease patient is in what stage
stage B
86
CHF patients are in what stages of heart disease
C, D
87
progression of heart disease
- some will develop clinical signs
- many will have heart enlargement
- most will remain asymptomatic
- varying by the study about 10% of dogs, cats, horses will develop heart disease
