Cardiovascular pathology

Question 1

What is a normal heart systolic ejection fraction?

Answer 1

60%

Question 2

Until what week of gestation does the foetus have 1 single chamber?

Answer 2

5th week of gestation

Question 3

What percentage of live births are affected by congenital heart disease?

Answer 3

1%

Question 4

What is the most common congenital heart disease?

Answer 4

Ventricular septal defects (25-30%)

Question 5

What is a patent ductus arteriosus?

Answer 5

Duct between pulmonary artery and aorta which persists after birth causing ongoing cardiac failure issues if not fixed.

Question 6

What is the second most common congenital heart disease?

Answer 6

Atrial septal defect (10-15%)

Question 7

What percentage of congenital heart disease are fallots?

Answer 7

4-10%

Question 8

What are the risk factors for atheroma & atherosclerosis?

Answer 8

Hypertension
Tobacco smoking
DM
Elevated cholesterol
Age, obesity, male, family history, OCP, sedentary life style

Question 9

How does atheroma initiate?

Answer 9

Endothelial dysfunction and injury occurs (smoking, HTN, etc.)
Lipids accumulate at site of impaired endothelial barrier
Local cellular proliferation and incorporation of oxidised lipoproteins
Thrombi on the surface with subsequent

Question 10

What are the complications of plaque rupture in atherosclerosis?

Answer 10

Complete occlusion due to thrombosis
Chronic narrowing of lumen with healing of local thrombus
Aneurysm change
Embolism of thrombus which can impact downstream smaller arteries
Dissection where the blood seeps into the plaque wall and blood leaks into intima

Question 11

What are the common presentations of atherosclerosis?

Answer 11

Angina
Myocardial infarction
Chronic congestive cardiac failure
Sudden death

Question 12

How can ischaemic heart disease cause angina, MI, congestive cardiac failure and sudden death?

Answer 12

Angina - too little blood flowing through coronary arteries causing chest pain (particularly worse on exertion)
MI - death of tissue downstream of area of narrowing causing significant damage to heart muscle and loss of heart pumping function
Chronic congestive cardiac failure - 75% of patients with cccf with dilated or failing hearts reflect ischaemic heart disease
Sudden death - failing heart will not carry electrical impulses as effectively and can lead to arrhythmias and sudden death. Sudden death typically occurs when lumen is >70% occluded.

Question 13

The complications of infarction differ depending on what area of the heart has been affected.
What area of the heart is usually affected in arrhythmias?

Answer 13

Arrhythmias usually occur when the supra and ventricular areas of the heart have been affected.

Question 14

What are some reasons for imperfect blood supply to the heart?

Answer 14

Atherosclerosis
Thrombosis
Thromboemboli
Artery spasm
Collateral blood vessels
Poor blood pressure, cardiac output and heart rate
Arteritis

Question 15

What is the risk of suddenly replenishing oxygen to tissues after an infarction?

Answer 15

Can cause significant haemorrhage and reperfusion injury where delivery of oxygen causes a further degree of injury as superoxide radicals are generated.

Question 16

What is an aneurysm?

What is the risk of an aneurysm forming in the myocardial wall?

Answer 16

Weakening of an artery wall which creates a bulge/distention of the artery and is at risk of rupture and life-threatening internal bleeding.
It if forms in the myocardial wall, it can cause disruption of blood flow and accumulation of blood in the heart sacs leading to thrombosis risk and subsequent embolism risk.

Question 17

What is dressler’s syndrome?

How is it treated?

Answer 17

Form of pericarditis which occurs 2-10 weeks following MI, pace maker insertion, cardiac surgery.
It it thought to be due to myocardial stimulating the production of autoantibodies against the heart muscle and leads to recurrent fever, chest pain, pleural or pericardial rub, cardiac tamponade.
Treat = aspirin, NSAIDs, steroids

Question 18

What is acute rheumatic fever?
How is it commonly caused?
Where is it most prevalent and who is most commonly affected?
What are the complications of rheumatic fever?

Answer 18

Systemic infection which affects heart, joints, brain and skin.

Rheumatic fever can develop from Group-B haemolytic streptococcus infection in the upper respiratory tract (Scarlet fever) if not treated properly.

It is most prevalent in developing countries and less common in developed countries.

Peak incidence 9-11 years of age but can also occur in adults.

Complications: Development of immunity against the streptococcal carbohydrate cell wall produces antibodies that cross react with cardiac myocytes and valvular glycoproteins and produces local inflammation, scarring and damage to valves.
Chronic scarring can lead to calcification of the valves and predispose patients to thrombosis and provides an ideal setting for bacteria within the blood stream to accumulate, increasing the risk of infective endocarditis.

Question 19

What is the most common cause of infective endocarditis?

Answer 19

Congenital heart disease as rheumatic fever cases have declined.

Question 20

What organisms typically cause infective endocarditis?

Answer 20

Commonly Streptococci and staphylococci but can be fungi and atypical bacteria also.

Question 21

What age group is calcified aortic stenosis most common in?

What valve variant causes calcified aortic stenosis to be diagnosed at an earlier age?

Answer 21

65-80 year olds

Earlier age if you have bicuspid valve variant.

Question 22

Is mitral valve prolapse more common in women or men?
What is the pathophysiology of mitral valve prolapse?
What are the associated risks of MVP?

Answer 22

More common in women (6% female population)
Mitral valves bow upwards into the left atrium allowing blood to leak back into the left atrium as the cusps do not close properly.
There is a strong association with connective tissue disorders (Marfans syndrome)
Associated risks: sudden cardiac death, IE

Question 23

What is myocarditis and what is the most common cause?

What are the more rare causes of myocarditis?

Answer 23

Inflammation of the myocardium often associated with pericardial inflammation.
A lot of cases are idiopathic
Most common cause is a viral infection (Enteroviruses, Adenoviruses, HHV6, EBV, Influenza, Hepatitis, Polio, Mumps, Rubeola Coxsackie, HIV)
More rarely = bacterial infection (staph, strep, diptheria) or fungi and parasites (toxoplasmosis, cryptococcus).
Certain drugs and medications can also cause. myocarditis -> lithium, cocaine, NSAIDs.

Question 24

What are the 3 most common groups of cardiomyopathy?

Answer 24

1. Dilated cardiomyopathy (DCM)
2. Hypertrophic cardiomyopathy (HCM)
3. Arrhythmogenic right ventricular cardiomyopathy (ARVC)

Question 25

What is dilated cardiomyopathy? | What is the typical end point?

Answer 25

Dilated, flabby, enlarged heart (2-3x normal weight) with unknown cause. 35% genetically linked Prevalence - 0.2% It can be secondary to conditions such as: - Ischaemia - MI - Valvular heart disease Many of the times there is no secondary cause - just big hearts. End point is usually arrhythmias and significant risk of sudden cardiac death.

Question 26

What is the leading cause of sudden cardiac death in the young? What is the pathophysiology and investigation of these conditions?

Answer 26

Hypertrophic cardiomyopathy (5-10%) - Condition where the heart muscle becomes abnormally thick causing LV outflow obstruction as there is asymmetrical septal hypertrophy. - Compensation occurs leading to a large heart - 70% have mutations in genes encoding B-myosin and a-tropomyosin and troponin T - Often strong family history of cardiac failure and sudden death - Poor prognosis if <14 age and presents with syncope and has family hx of sudden cardiac death Investigations - ECHO showing an asymmetrical septal hypertrophy & small LV cavity. - Family history - ECG showing LVH, progressive T wave inversion, deep Q waves

Question 27

What is arrhythmogenic right ventricular cardiomyopathy (ARVC)?

Answer 27

RV myocardium is replaced with fibro-fatty material and inflammation. Very common disorder (1 in 5000) Often runs in families - strong familial genetic linkage (chromosome 14, 1 & 2)

Question 28

What is restrictive cardiomyopathy? What is the most common cause of RCM and what occurs? What are other causes of RCM?

Answer 28

Form of cardiomyopathy where the walls are rigid but not thickened = heart is restricted from stretching and filling with blood properly. As a result, the blood backs up into the circulatory system and can cause fluid buildup in lungs and body. It is the least common out of the cardiomyopathies. Amyloid = most common cause of RCM - More common in the elderly - Amyloid protein infiltrates into the myocytes, valves and blood vessels causing a firm, enlarged heart. - Can cause deterioration of left and right side of the heart and risk of sudden death Sarcoid - Chronic granulomatous disease causing scarring of the heart Haemochromatosis - Iron overload in heart and body Scleroderma - Disease causing hardening of tissues in the body

Question 29

What is the most common primary cardiac tumour? | What are the symptoms/complications?

Answer 29

Myxoma = tumour of primitive connective tissue commonly found in the heart - More common in females Complications - Valvular obstruction, embolism, fever, dysrhythmias, chest pain and sudden death.

Question 30

What is vasculitis? What are the causes? What is the most common type of vasculitis?

Answer 30

Inflammation of the blood vessels Causes - Deposition of immune complexes - Direct attack on vessels by antibodies - Cell mediated immunity - Viral infection - Serum sickness Most common type = granulomatous giant cell arteritis - Chronic and granulomatous inflammation of temporal arteries - Affects more females and usually in those over 70 - Cam also affect large arteries (aortic aneurysm and dissection) - Thickened blood vessel is often palpable. - Can cause blindness and headaches if affecting blood vessels around the head and eyes. - Thrombosis can occur in acute cases.

Question 31

How does abdominal aortic aneurysm increase risk of thrombosis and sudden death?

Answer 31

- They are almost always due to atheroma - As vessel buldges out, it allows blood to become stagnant and causes vascular thrombosis - As it progressively enlarges, it is at risk of spontaneous rupture and sudden death.

Question 32

What is a berry aneurysm? | What is a risk factor for berry aneurysms?

Answer 32

Sac-like, round, vascular dilation in the blood vessels in the brain (tend to occur where the main vessels meet, at circle of willis) - Long standing hypertension can cause weakness. within the arterial substructure. - There is a risk of subarachnoid haemorrhage and sudden death

Question 33

What is a dissecting aneurysm? | What are the risk factors for dissecting aneurysm?

Answer 33

Dissecting aneurysms occur when there is a tear in the intima of the vessels, allowing the blood vessel to be stretched. Can be seen in cases of HTN or degenerative arterial diseases such as Marfans syndrome.

Question 34

What 3 things increase the risk of thrombosis? (Virchows Triad)

Answer 34

1. Endothelial injury 2. Stasis or turbulence of blood flow 3. Increased blood coagulation

Question 35

What is Ehlers Danlos syndrome? | How many types are there and which is considered the most serious? What are the vascular effects?

Answer 35

Heterogenous group of disorders with abnormal collagen synthesis There are 13 types of EDS Most serious type is considered the vascular EDS (type 4) where there is risk of sponatenous rupture and aneurysm formation in early adulthood (usually affects large arteries such as aorta and abdomen arteries)

Question 36

What is Marfans syndrome? What are the typical features of Marfans syndrome? What are the effects on the heart?

Answer 36

Marfan syndrome is a disorder of the body's connective tissues. Hereditary condition - autosomal dominant Typical characteristics of Marfan syndrome include: - being tall - high arched palate - abnormally long and slender limbs, fingers and toes (arachnodactyly) - heart defects - lens dislocation – where the lens of the eye falls into an abnormal position Heart effects - Mitral valve prolapse - Aortic dissection