Cardiovascular pathology

Question 1

What is the most common cause of cardiac disease?

Answer 1

Atherosclerosis - 80%
Hypertensive heart disease - 9%

Question 2

What are the key differences in the histology of a muscular and elastic artery?

Answer 2

Elastic -> closer to heart - concentric rings of elastic and muscular tissue
Muscular -> clear internal and external elastic lamina

Question 3

What are the key histological layera of a muscular artery?

Answer 3

Tunical intima (endothelium)
Internal elastic lamina
Tunica media (smooth muscle)
External elastic lamina
Tunica adventitia

Question 4

What are the features of smooth muscle fibres?

Answer 4

No striations
Spindle shaped
Single central nucleus

Found in blood vessels, GIT, hollow organs etc

Question 5

What are some key risk factors for atherosclerosis?

Answer 5

Increasing age
High cholesterol and TG
High BP
Smoking
Diabetes
Obesity
Physical inactivity
High saturated fat diet

Question 6

At what stage of occlusion is an atheroma classified as a symptomatic?

Answer 6

70% obstruction of the lumen

Question 7

What is the key pathology shown in this vessel?

Answer 7

An atheroma

Question 8

What histological features may be seen in an athermoa?

Answer 8

Brown spots -> calcification
Fibrous cap -> collagen and elastin
Cholesterol crystals/clefs and foam cells -> white spaces

Question 9

What are the key complications of atherosclerosis?

Answer 9

Erosion, ulceration or rupture
Induces thrombosis -> ACS
Aneurysm formation
Atheroembolism

Question 10

How do the layers of blood vessels relate to the layers of the heart?

Answer 10

Endocardium = tunica intima
Myocardium = tunica media
Epicardium = tunica adventitia

Outer pericardium -> parietal layer (fibrous and adipose), visceral layer

Question 11

How does a subendocardial/transmural myocardial infarction relate to the anatomy of the coronary arteries?

Answer 11

Arteries in the epicardium
The innermost myocardium (just superficial to endocardium hence subendocardial) is the furthest away -> longer perfusion distance -> hence dies first in infarction.

Question 12

On gross pathology what does an area of infarction look like?

Answer 12

Yellow/lightish tinge

Question 13

What are the histological features of cardiac muscle?

Answer 13

Striated
Branching
Single circular nucleis
Intercalated disks
Rectangular shape

Question 14

What are the histological features of MI from 6hrs to 24hrs?

Answer 14

Widened spaces between myocytes due to oedema
Loss of nuclei
May also see haemorrhage (lots of rbcs) - not shown in this image

Question 15

What are the histological features of 1-3days post MI of myocardium?

Answer 15

Inflammatory cells - neutrophils
Large areas of oedema and muscle loss

Question 16

What are the histological features 3d to 2w post MI of myocardium?

Answer 16

Majority is inflammatory cells including macrophages (clear necrotic myocytes)
Damages area replaced by vascularised granulation tissue in 1 -2 w.

Question 17

When should PCI be offered to treat a STEMI?

Answer 17

If present within 120 mins of symptom onset
AND - can be given within 120mins of when fibrinolysis could have been given.

Question 17

What are the histological features of well healed myocardial infarction (scar tissue) 2-6 weeks?

Answer 17

Dense collagenous fibrous tissue
Light pink sheets with no nuclei
May have some residual myocytes

Question 18

What is the gold standard test for diagnosis of myocarditis?

Answer 18

Endomyocardial biopsy.

Question 19

What is the most common viral cause of myocarditis?

Answer 19

Coxsackie virus

Question 20

What are the key infectios disease causing myocarditis?

Answer 20

Viral - coxsackie, parvovirus B19, HHV 6
Bacterial - chlamydiae, borellia

Rickettsia
Plasmodium
Toxoplasma

Question 21

What immune mediated causes of myocarditis?

Answer 21

Post infections/viral
Post streptococcal (Rheumatic fever

Systemic inflammatory disorders such as SLE

Drug hypersentivities - antibiotics, vaccines, anticonvulsants

Question 22

What are the key histological findings of myocarditis?

Answer 22

Myocardium -> interstitial inflammatory infiltrate
Myocyte damage - nucleus loss

Question 23

What are the key histological findings in the image of myocardium?

Answer 23

Multinucleated giant cells (from fusion of macrophages)
is a giant cell myocarditis

Question 24

What is the key management of myocarditis?

Answer 24

Treat cause: if infective antivirals etc, if immune mediated corticosteroids Supportive Most patients recover spontaneously

Question 25

What is a potential complication of myocarditis?

Answer 25

Dilated cardiomyopathy

Question 26

What are some predisposing factors for infective endocarditis?

Answer 26

Rheumatic heart disease Mitral valve prolaspe Degenerative calcific valvular stenosis Artificial (prosthetic) valves

Question 27

What are the common sources of infection in infective endocarditis?

Answer 27

Dental or surgical procedure IVDU Ivasive vascular procedure (central lines)

Question 28

What are the common causative organisms of infective endocarditis?

Answer 28

Streptococcus viridans (from oral cavity) Staph aureus (skin - IVDU) or hospital acquired Enterococci HACEK

Question 29

What is key for the diagnosis of infective endocarditis?

Answer 29

3 sets of blood cultures Transthoracic or transesophageal echo

Question 30

What is the key histological features of infective endocarditis?

Answer 30

Neutrophil Bacterial colonies (Dark purple)

Question 31

What are some potential complications of infective endocarditis?

Answer 31

Septic emboli - pyogenic brain abcess, stroke Roth spots (retina) Septic pulmonary emboli Peripheral fingers infacts Aortic valve perforation Mitral valve regurg Acute heart failure (from acute valve failure

Question 32

What is nonbacterial thrombotic endocarditis?

Answer 32

Deposition of small sterile thrombi on leaflets of cardiac wall Common in debilitated patients - cancer, sepsis Thrombi loosely attach so can become embolic

Question 33

What is endocarditis of SLE? (Libman-sacks)

Answer 33

Small sterile vegations on cardiac valves of patients with SLE Vegetations = finely granular fibrinous and eosinophilic material.

Question 34

What is the difference between systolic and diastolic heart failure?

Answer 34

Systolic failure – left ventricle (LV) loses ability to contract (pump) – measured using LV ejection fraction Diastolic failure – left ventricle has reduced ability to fill (stiffness) and is unable to fill with blood between heart beats

Question 35

What are the typical causes of systolic heart failure?

Answer 35

CAD Arterial HTN Valvular heart disease (volume load) Arrhthmia INflammatory Idiopathic/toxic cardiomyopathy

Question 36

What are the typical causes of diastolic heart failure?

Answer 36

Diabetes mellitus Arterial HTN Valvular heary disease (pressure load) Hypertrophic cardiomyopathy Restricted cardiomyopathy Constrictive pericarditis Amyloidosis