Diseases Flashcards
(74 cards)
1
Q
what is heart failure?
A
inability of the heart to maintain a normal CO at normal filling pressures
2
Q
What is right sided heart failure?
A
- increased filling pressure of the right side
- retained fluid in systemic veins
3
Q
what is left sided heart failure?
A
- increased filling pressure on the left side
- retained fluid in pulmonary veins
4
Q
what are 5 categories of causes of heart failure?
A
- pump failure
- volume overload
- pressure overload
- arrhythmias
- diastolic failure
5
Q
how can pump failure cause heart failure?
A
-failure of contractility of heart muscle so cant maintain normal CO
6
Q
examples of causes of pump failure?
A
DCM, coronary vascular disease
7
Q
how can volume overload cause heart failure?
A
-chronic increase in amount of blood to be pumped from a specific chamber so abnormal CO
8
Q
examples of causes of volume overload?
A
blood shunting (VSD / PDA)
blood regurgitation - MVD
anaemia
high metabolic demands
9
Q
how can pressure overload cause heart failure?
A
increased resistance to emptying of a chamber so reduced CO
10
Q
examples of causes of pressure overload?
A
hypertension
aortic / pulmonary stenosis
11
Q
how can arrhythmias cause heart failure?
A
-compromised CO because of tachy/bradycardia
12
Q
how can tachy/brady cardia affect CO?
A
- tachycardia - shorter diastole and impaired filling
- bradycardia - limited CO by limited HR
13
Q
how can diastolic failure cause heart failure?
A
-impaired ventricular filling so low CO
14
Q
what can cause diastolic failure?
A
-pericardial tamponade, HCM
15
Q
how can heart failure be classified?
A
forward / backward
R or L
cause
16
Q
what is forward heart failure?
A
inadequate output at normal pressure
17
Q
what is backward heart failure?
A
- congestive
- adequate output at abnormal pressures
18
Q
what is forward and backward heart failure?
A
inadequate output at abnormal pressures
19
Q
What is the short term response to heart failure?
A
- low bp cause increase in sympathetic tone
- symp acts on b receptors to cause +ve chronotrope, +ve inotrope , +ve lusitrope , renin release
- symp acts on a receptors to cause vasoconstriction
20
Q
what is the medium term response to heart failure?
A
- RAAS - vasoconstriction, salt and water retention, modified cardiac myocytes and fibroblasts = increased vol, increase CO and increased bp (but excess fluid is an increased burden on heart)
- ADH release from low bp causing more vasoconstriction and water retention
- NP release from chamber wall stress causing vasorelaxation and increased sodium loss
21
Q
what is the long term response to heart failure?
A
- hypertrophy (increase in cell size)
- initially beneficial until myocardium outgrows blood supply so get regional ischaemia
- eccentric from volume overload
- concentric from pressure overload
22
Q
what does eccentric hypertrophy look like?
A
-normal wall thickness but increased internal and external diameter
23
Q
what does concentric hypertrophy look like?
A
-increased wall thickness, decreased internal diameter but normal external diameter
24
Q
How can the compensatory mechanisms be detrimental long term?
A
- excess fluid retention causes congestion
- increased cardiac work from increased afterload
- hypertrophy causes worse myocardial performance
25
what is different about a reptiles ECG?
-have an SV wave before p waves from there extra sinus venosus chamber contracting
26
where would you find a snakes heart?
1/5 - 1/3 along body
27
what are the 3 main disease categories to think of in LA?
pericarditis
bacterial endocarditis
cardio-pulmonary disease
28
what is the main cause of pericardidits in pigs and what are the clinical signs?
- bacterial - haemophilus parasuis, strep.suis
| - fever, depression, fibrinous poly serositis, CNS/pleural / peritoneal effusion, death
29
what are the 2 causes of pericarditis in cattle?
- septic from hardware disease
| - lymphosarcoma from bovine leukaemia virus
30
what are the signs seen with cattle pericarditis?
- septic fluid, cheesy exudate, adhesion, gas in pericardium, fever, anorexia, depression
- venous congestions, peripheral oedema, RSHF
31
what are some ways to diagnose hardware disease in cattle?
- williams test (grunt of pain in trachea when rumen contracts)
- bar test
- pinch test
- rads / Us
32
what can cause pericarditis in horse?
- idiopathic
| - EVA, flu, strep, E.coli, actinobacillus
33
what are the signs of pericarditis in the horse?
venous distension, ventral oedema, muffled heart sounds, pleural effusion
34
how do you diagnose and treat pericarditis in the horse?
- diagnose by ECHO - fibrin in sac
- ECG - small QRS complexes
- repeated drainage and lavage
35
what is bacterial endocarditis normally secondary to? esp FA and equids
bacteraemia
FA - liver abscess, mastitis
Equid - septic jugular thrombophlebitis
36
what are the signs of bacterial endocarditis and how is it diagnosed?
- CHF, murmur, fever, tachycardia, tachypnoea
| - hyperfibrinogenaemia, anaemia, leucocytosis
37
what is cor pulmonale?
cario-pulmonary disease secondary to pulmonary hypertension in cattle
- high altitude acidosis
- chronic pulmonary and vascular disease
38
what are the clinical signs of cor pulmonale in cattle and what should you do?
- hypertrophy and dilation and RV failure
- subQ oedema, jugular distension and pulsation, dyspnoea, tachypnoea, tachycardia, murmur
- move to lower pastures but pretty helpless as lung pathology already established
39
what is EIPH?
exercise induced pulmonary haemorrhage
- cardio-pulmonary disease of horses
- normally from caudodorsal lobe as higher blood flow
40
what are the clinical signs of EIPH?
bilateral epistaxis, tracheal blood
- poor performance, swallowing after exercise
- cardiac/resp signs
41
how do you diagnose EIPH in horses?
- haemorrhage from pulmonary not bronchial lesions
- endoscopy
- BAL - RBC, haemosiderophages
- Rads - interstitial opacity
42
what is the prognosis with EIPH?
- good if can treat cause and doesnt affect performance (commonly happens in horses post exercise)
- poor prognosis if idiopathic and is affecting performance
43
name 4 acquired cvs disease in cats?
- hypertrophic CM
- dilated CM
- restrictive CM
- arrhythmogenic RV CM
44
in cats what is the pathophysiology of HCM?
- idiopathic
- concentric LV hypertrophy
- dynamic LV outflow tract obstruction (DVOTO) due to abnormal motion of anterior mitral valve leaflet in systole (SAM) blocking the outflow tract
- may have enlarged L and R atria
45
what is the common clinical presentation of HCM in cats?
- young adult males
- all breeds
- asymptomatic
- varying intensity systolic murmur
- CHF, aortic thromboembolism, sudden death, gallop sounds, tachypnoea, crackles
46
how is HCM diagnosed in the cat and what affects the prognosis?
- Rads - LV hypertrophy, pulmonary oedema, pleural effusion
- Echo - LV hypertrophy, SAM (systolic anterior mitral valve motion)
- prognosis worse if have clinical signs
47
what is the pathophysiology of DCM in the cat?
- dilation of all 4 chamber
- thin ventricular walls
- hypokinetic LV (systolic dysfunction)
48
what is the normal clinical presentation for a cat with DCM?
- can be from taurine deficiency
- middle - old age
- hypotension, hypothermia, bradycardia
- quiet / absent murmur
- gallop rhythm
- thromboembolism
49
how is DCM diagnosed and what is the prognosis in the cat?
- Echo - dilated LV with FS 12mm
| - grave prognosis
50
what is the pathophysiology of restrictive CM in the cat?
- stiff LV but with normal dimensions
| - marked atrial dilation
51
what is the common clinical presentation for cats with restrictive CM?
- older
- dyspnoeic
- aortic thromboembolism
- arrhythmia
52
how do you diagnose restrictive CM in cats?
Echo - biatrial enlargement
53
what is the pathophysiology of ARVC? (arrhytmogenic RV cardiomyopathy)
- fibrofatty infiltration of RV
| - R heart enlargement
54
what is the presenation of a cat with ARVC?
sycope
| RSHF
55
how do you diagnose ARVC in cats?
severe RV + RA dilation
| tricuspid regurgitation
56
what test can be used as a marker for cats at risk of cardiomyopathies?
NT - proBNP test
57
with HCM in the cat what is the different stages of treating an asymptomatic cat?
- no gallop / arrhytmia and normal LA - no treatment
- LA dilated - ACE i , clopidogrel and aspirin to stop thromboemboli
- LV outflow obstruction - atenolol
58
how does an aortic thromboembolism come about?
-thrombus in left auricle from altered endometrium causing platelets to be activated -- dislodges -- stuck in aortic bifurcation -- severe acute paresis and pain
59
what are the 3 main dog diseases?
- valvular disease
- DCM
- pericardial effusion
60
what is the common signalment for mitral valve disease in dogs?
- old
| - small breed - cavalier king charles, terriers, poodles
61
what is the pathophysiology of mitral valve disease in dogs?
- slow progression
| - get signs of LSHF in late disease due to LS volume overload secondary to regurgitation from valve damage
62
what would be the clinical signs expected with MVD?
- left apical systolic murmur
- tachycardia
- low BCS
- LSHF signs - dyspnoiec, cough, crackles, exercise intolerant, collapse
63
how do you diagnose MVD in dogs?
- doppler echo
| - Rads - LA and LV enlarged
64
how do you treat MVD in dogs?
- dont treat until in heart failure
| - treat normal HF 4 drug therapy - furosemide, pinobendan, spironolactone and ACE i
65
what is the common signalment for DCM in dogs?
- large breed
| - older
66
what is the pathophysiology of DCM in dogs?
- progresses to heart failure
| - primary systolic failure of the myocardium
67
what clinical signs would be seen in a dog with DCM?
- arrhythmia
- soft left apical systolic murmur (from dilation)
- HF signs
68
how do you diagnose DCM in a dog?
- Echo - dilated and low FS
- ECG if rhythm distrubance
- cardiomegaly on rads
69
how do you treat a dog with DCM?
- pimobendan and ACE i to delay HF signs
| - 4 drug therapy once in HF
70
what is the normal signalment for pericardial effusion in dogs?
- old
| - labrador, GSD, st.bernards
71
what is the pathophysiology of pericardial effusion in the dog?
- causes compression of the heart and diastolic dysfunction due to fluid build up
- can be idiopathic or due to a neoplasm
- can get cardiac tamponade when pressure of fluid is higher than R heart so compresses it affecting its function
72
what will be the clinical signs of a pericardial effusion in dogs?
- signs of forward failure due to inadequate output and backward failure due to congestion
- muffled heard sounds
- decreased intensity of apex beat
- pulsus paradoxus
- no murmur and no rhythm disturbance
73
how is pericardial effusion diagnosed?
- Echo - fluid
- Rad - enlarged silhouette
- ECG - may see decreased QRS amplitude
74
how do you treat a pericardial effusion?
-pericardiocentesis on R thorax under US guidance
