Cardiovascular Disease Flashcards
On an ECG what does each of the following show?
a) P wave
b) PR interval
c) QRS complex
d) T wave
a) Atria depolarising and physically contracting
b) Gap where bundle of His creating a pause
c) Ventricles contracting
d) Ventricles repolarising
What are the 3 main sites of atherosclerosis?
- Coronary arteries = ischaemic heart disease (angina, MI, heart failure)
- Cerebral circulation and carotids = stroke
- Legs = peripheral vascular disease (gangrene), small bowel ischaemia
What is an aneurysm and what can they look like?
Weakening of blood vessel wall resulting in ballooning
- Sacular aneurysm on side of artery
- Fusiform aneurysm whole artery dilates
What are the a) reversible and b) non-reversible risk factors for atherosclerosis?
a) Diabetes, smoking, hypertension, hyperlipidaemia (raised LDLs), obesity
b) Age, male sex, post menopausal, family history
Where is a a) pulmonary embolus b) peripheral embolus usually from?
a) DVT
b) Aorta e.g. abdominal aneurysm down into leg
What are the different causes of heart failure?
- Valve stenosis or regurgitation
- Ischaemic heart disease (damage from MI)
- Sustained arrhythmia
- Hypertension causing damage to heart muscle
- Cardiomyopathy
- COPD - cor pulmonale (RHS HF from pulmonary hypertension)
- Excessive demand e.g. anaemia, hyperthyroidism
What is the definition of generalised atheroma?
Many lesions in arteriole walls become fibrotic and calcified with deposition of Ca salts - a sclerotic process causing hardening
How does atherosclerosis form?
1) Fatty streak
2) Fibrolipid plaque
3) Complicated lesion
What is the difference between a muscular artery and an elastic artery?
In muscular, tunica media has smooth muscle cells, elastic tissue found throughout wall in elastic
How does a fatty streak form?
1) Endothelial damage
2) Permeability - lipids enter intima
3) Monocyte adhesion to endothelium (precursors of macrophages)
4) Entry of LDLs and smooth muscle cells come through internal elastic lamina
5) Foamy macrophages take up LDLs but cant digest it, forming a fatty streak
How does a fibrolipid plaque form?
1) Smooth muscle cells migrate to surface along with fibroblasts
2) Cell proliferation
3) Lipid uptake
4) Production of collagen - part of the repair process but causes damage
5) Macrophage breakdown and forms a lipid lake. Can see cholesterol crystallising out
Endothelial lining still intact!
How does a complicated lesion form?
1) Impaction of platelets onto the surface
2) Fibrolipid plaque becomes ulcerated
3) Clotting cascade causes thrombus formation on surface of plaque
4) This sits over the lipid lake and calcification of tissue occurs creating a mass
5) Further fibrosis weakens artery wall, fissure breaches plaque which can rupture into luman
6) Can occlude whole artery
7) Thrombus can break off and cause embolism
8) Weakened wall can form aneurysm
How what features show that the atheroma is a stabilized plaque?
- Small lipid pool
- Fibrous cap
- Preserved lumen
How is atherosclerosis managed medically?
- Beta blockers (reduce BP)
- Angiotensin-converting enzyme (ACE Inhibitors)
- Diuretics
- Anti-platelet meds
- Cholesterol meds (reduce LDL levels)
- Fibrinolysins (dissolve thrombi)
- Calcium channel blockers
How is atherosclerosis managed surgically?
- Angioplasty (surgical modification of arteries)
- Bypass
- Stent
- Endarterectomy (internal lining with plaque removed)
In Virchow’s Triad, what are the 3 things that may result in thrombosis?
1) Changes to the intimal surface of a vessel e.g. atherosclerosis
2) Changes to the pattern of blood flow e.g. venous stasis or injury to blood vessel
3) Changes in blood constituents e.g. hypercoagulable blood
What is the appearance of arterial thrombosis histologically?
Lines of Zahn
Pale = platelets and thrombin, Dark = RBCs
What are the risk factors for venous thrombosis?
- Burns and trauma
- Surgery
- Cardiac failure
- Pregnancy
- Immobility
- Long haul flight
What is the definition of
a) Thrombophlebitis
b) Phlebothrombosis
a) Inflammation of the deep vein
b) Stasis with no inflammation from platelets
Why might
a) Atrial thrombosis occur?
b) Valvular thrombosis occur?
c) Ventricular thrombosis occur?
a) - Mitral stenosis
- Atrial fibrillation
b) - Endocarditis
- Rheumatic fever
c) Following MI as dead heart muscle disrupts endothelium
What are the 4 fates of thrombi?
1) Lysis and resolution - given fibrinolysin
2) Retraction and recanalization (relinied with endothelium)
3) Organisation and scarring
4) Embolism (breaks off)
In a pulmonary embolism
a) Where is the embolus originally from?
b) What happens if it blocks entire pulmonary artery?
c) What happens if it blocks branch of pulmonary artery?
d) What happens if it blocks small arteries?
a) DVT or pelvic veins
b) Sudden death
c) Chest pain and breathlessness, wedged shaped ischaemia
d) Pulmonary hypertension
Where is a systemic embolism originally from?
Arterial side i.e. thrombosis on LHS heart or thrombi formed on atheromatous plaques
What are the causes of infarction?
- Atheroma
- Hyperviscosity
- Compression (tumour or injury)
- Embolism
- Thrombosis
- Vasculitis (inflammation vessel wall)
What happens to tissue after infarction and what occurs to the cellular material?
- Autolysis
- Enzymes released dissolve cellular material
- Nucleus breaks up = karyorexis
In a myocardial infarction, what is seen in the heart muscle at:
a) Less than 6 hours
b) 24-48 hours
c) Several days
d) Several weeks
a) Only ECG changes
b) Pallor with red rim
c) Pallor with red rim and softened
d) Grey and fibrotic
What is the definition of
a) False aneurysm
b) Dissecting aneurysm
c) Mycotic aneurysm
a) Blood filled space due to vasculature rupture (Haematoma)
b) Damage to intima of vessels, blood dissecting layers of wall apart
c) Related to infection
Why is the jugular venous pressure raised in heart failure?
Backlog of blood making right side of heart under pressure
How is angina managed?
- GTN spray to shorten attack
- Anti-anginal drugs: beta-blockers, nitrates, CCB, nicorandil, aspirin etc
Give examples of cardiac investigations
- ECG
- Chest Xray
- Echocardiogram
- Stress tests
- Coronary angiogram (invasive)
- CT/MRI
- Troponin levels
What are the common valve problems:
a) AS
b) MR
c) TR
d) MS
a) Aortic stenosis (narrowing with age)
b) Mitral Regurgitation
c) Tricuspid regurgitation (from heart failure or chronic lung disease)
d) Mitral Stenosis (usually from rheumatic inflammation)