Cardiology Flashcards
(42 cards)
1
Q
Cardiac myocytes lack
A
plasticity
(limited ability to respond to stress)
2
Q
Mature cardiac muscle response to injury
A
- healing is by fibrosis
- Atrophy-reversible
- Hypertrophy-reversible
- Degeneration-sublethal
- Necrosis-lethal
3
Q
Histopath of heart
A
unlikely to result in specific dx
4
Q
Heart failure
A
- endpoint rather than specific disease
- dec myocardial contractility
- decreased compliance (fibrosis)
- dysrythmias/arrythmias
5
Q
Endocardium
A
- Innermost layer of heart
- lines
- ventricles
- atria: thicker in atria than ventricles (can look white grossly)
- extends over chordae tendinae
6
Q
Vascular supply of the heart
A
- left and right coronary artery arising from aorta
7
Q
A
8
Q
Epicardium
A
- outermost layer contiguous at cardiac base with pericardium
- entire inner surface of pericardial cavity lined by mesothelium
9
Q
Systematic examination of the heart
A
Follow normal blood flow
RA - RV - MPA - LA - LV - aorta
10
Q
Routine sections for histopath (2)
A
- papillary muscle
- mitral valve
11
Q
Artifacts
A
- Post mortem clots: red ‘currant jelly’ clots not attached to endocardium
- Chicken fat clots in horses
- Red staining endocardium: RBC lysis (hemoglobin imbibition)
- Euthaniasia solution after a cardiac stick
12
Q
SA node
AV node
R and L bundle branches
A
- junction of cranial vena cava and RA (free wall)
- bundle of HIs: beneal septal leaflet of right AV valve w/in interventricular septum
- ramify over ventricle as purkinje fiber: subendocardial
13
Q
Cardiac compensation
A
- dilation
- hypertrophy
- inc heart rate
- inc in peripheral resistance
- inc in blood volume
- redistribution of blood flow
*failure of compensation: decompensation (heart failure)
14
Q
DIlation
A
- structural compensation
- maintains connections and architecture
- stretching of myofibers
- often degenerative
- result of chronic overload
15
Q
hypertrophy
A
- structural compensation
- inc in mass not cell number
- results from pressure overload
16
Q
Mechanical compensation
A
- inc HR
- inc peripheral resistance
- inc in blood volume
- redistribution of blood flow
- baroreceptors: look for pressure drops and compensate with VOLUME
- not pumping well, poor pressures
- shunting
17
Q
Cardiac hypertrophy
A
- compensatory mechanism that requires
- time
- healthy myocardium
- adequate myocardial nutrition/oxygenation
18
Q
Causes of Right ventricular hypertrophy
A
- pulmonary hypertension
- congenital abnormalities
- tricuspid (Right AV) incompetence
- mechanical obstruction: dirofilarisis
19
Q
Cor pulmonale
A
- right ventricular hypertrophy from long-term pulmonary hypertension
20
Q
Causes of Left ventricular hypertrophy
A
- systemic hypertension
- renal dz
- congenital abnormalities
- aortic stenosis
- mitral incompetence
- Endocrine disease
- hyperthyroidism
- acromegaly
21
Q
Clinical Syndromes of Cardiac Decompression
A
- Cardiac Syncope; acute cardiac failure
- Congestive Heart Failure; chronic loss of pumping ability
22
Q
Cardiac Syncope; acute cardiac failure
A
- Arrythmias, massive necrosis, v-fib, heart block
- extreme changes in blood pressure and heart rate
- symptoms - collapse, loss of consciousness
23
Q
Congestive Heart Failure; chronic loss of pumping ability
A
- Clinical sign and not a disease
- Forward failure: decrease flow to peripheral tissue
- Backward failure: Accumulation behind the failing chamber
24
Q
Cycle of cardiac decompensation
A
- Cardiac Decompensation: Hypoxia
- renal: inc renin release (RAAS)
- renal: stimulates erythropoesis (EPO)
- polycythemia -> in blood viscosity
- Aldosterone release inc sodium and water retention
- Plasma volume inc Hypervolemia and edema
- Result: failing heart must pump more, thicker fluid
25
Aldosterone release increases....
* Sodium and water retention
26
Syndromes of cardiac decompensation
* Congestive heart failure
* Left Heart Failure
* Right Heart Failure
27
Right Heart Failure
Causes
* Valvular insufficiency
* Tricuspid (right AV) valve
* Pulmonary valve
* Pulmonary hypertension
* obstruction of forward flow
* Cardiomyopathy
28
Right Heart Failure
Sequelae
* Hepatic Congestion (nutmeg liver, hepatomegaly)
* splenomegaly
* Ascites (more common in dogs)
* Hydrothorax (more common in cats)
* Pleural and pericardial effusion
29
Left Heart Failure
Causes
* Myocardial loss of contractility
* myocarditis
* cardiomyopathy
* Valvular insufficiency
* mitral (Left AV) valve
* aortic valve
* Congenital defects
* PDA
30
Left Heart Failure
Sequelae
* Pulmonary congestion
* Pulmonary edema
* Pulmonary Fibrosis (will cause hypertension)
31
Top ddx for cardiac disease in dogs
* Endocardiosis
* Congenital disease
* DCM
* Hemopericardium
32
Top ddx for cardiac disease in cats
* HCM
* DCM
* Hyperthyroidism associated hypertrophy
* Congenital disease
33
Problem oriented approach
* D: Degenerative
* A: Anomaly (Congenital)
* M: Metabolic
* N: Neoplastic, Nutritional
* I: Inflammatory, Infectious, Immune-mediated
* T: Trauma, Toxicity
* V: Vascular
34
Patent Ductus Arteriosus
* RV and LV hypertrophy
* L -\> shunt usually
* LA dilation
* R -\> L shunt if severe -\> cyanosis
* Dilation of PA and aorta, jet lesions in pulmonary artery
35
Aortic Stenosis
3 types
* Valvular
* Subvalvular
* Supravalvular
36
Subvalvular aortic stenosis
* concentric hypertrophy LV
* Fibrous endocardial thickening
* Post stenotic dilation aorta with jet lesions
* Myocardial necrosis
* subaortic stenotic ring
37
Pulmonic Stenosis
Sequelae
* Right ventricular hypertrophy
* Post stenotic dilation of pulmonary artery
* Muscular hypertrophy of RV outflow tract can complicate stenosis
38
Valvular dysplasia
* Malformation of valve leaflets
* leaflets may be attached to the septum
* common in cats and labrador retrievers
39
Septal Defects
* VSD most common
* Pulmonary hypertension from blood shunting from Left to Right
* right ventricular hypertrophy
* inc in pulmonary hypertension can lead to eventual compensatory right to left shunting
40
Ventricular septal defects
* Can be assoc with other cardiac defects
* Can occur either high or low (high more typical)
* Left to right shunt -\> pulmonary hypertension
* Severe cases reverse shunting -\> cyanosis
41
Tetrology of Fallot
1. Pulmonary Stenosis
2. Dextroaorta
3. High Ventricular Septal Defect
4. Right Ventricular Hypertrophy
42
Abnormalities of Aortic Arch
* Persistent right aortic arch
* Double aortic arch
* anomalous subclavian arteries
