Hypertension, Ischaemic Heart Disease and Cardiac Failure

Question 1

Where does hypertension occur

Answer 1

It can occur in either the systemic or pulmonary circulation however is more difficult to diagnose in the pulmonary circulation.

Question 2

What is the formula for blood pressure

Answer 2

Blood pressure (BP) = cardiac output (CO) X peripheral resistance (PR)

Question 3

What is the difference between primary and secondary hypertension

Answer 3

Primary/essential hypertension occurs on its own. Secondary hypertension occurs due to an underlying cause.

Question 4

What is malignant hypertension

Answer 4

Malignant hypertension is when there is acute end organ damage as a result of hypertension.

Question 5

What is hypertension

Answer 5

Sustained resting blood pressure above a certain level.

Question 6

Above what value is blood pressure considered to be high in most instances

Answer 6

140/90 mmHg

Question 7

What determines the severity of hypertension

Answer 7

Diastolic pressure

Question 8

What is more dangerous acutely - increased systolic or diastolic pressure?

Answer 8

Systolic as this can lead to haemorrhage.

Question 9

What are some secondary causes of hypertension

Answer 9

Renal disease (which can also be caused by hypertension), endocrine disease, drug treatment, coarctation of the aorta

Question 10

What are the risk factors for primary hypertension

Answer 10

• Genetic Susceptibility
• High salt intake
• Chronic stress
• Abnormalities in the renin-angiotensin system which controls blood volume and blood pressure
• Obesity
• Diabetes

Question 11

What is benign hypertension

Answer 11

Where there are slow changes in the vessels and heart resulting in chronic end-organ dysfunction (as opposed to rapid changes and acute end-organ dysfunction).

Question 12

Which organs are susceptible to the end-organ effects of hypertension

Answer 12

The heart, the kidney, the brain, the vessels.

Question 13

Why is the retina important in hypertension

Answer 13

The retina acts like a window into the blood vessel system.

Question 14

What technique can be used to see end-organ damage as a result of hypertension

Answer 14

Retinoscopy

Question 15

What are the end organ effects on the heart due to hypertension

Answer 15

Left ventricular hypertrophy, coronary artery atheroma, ischaemic heart disease and cardiac failure.

Question 16

What are the complications of left ventricular hypertrophy

Answer 16

Fibrosis and arrhythmias

Question 17

What are the end organ effects on the kidney due to hypertension

Answer 17

Nephrosclerosis, “drop-out” of nephrons due to vascular narrowing, proteinuria, chronic renal failure

Question 18

How do you assess renal dysfunction

Answer 18

Check the urine.

Question 19

What are the end organ effects on the brain due to hypertension

Answer 19

Aneurysm resulting in intracerebral haemorrhage causing stroke.

Question 20

What vascular changes other than atheroma result from hypertension

Answer 20

Hyaline change and fibrinoid necrosis.

Question 21

What can be seen in retinoscopy if benign hypertension is present

Answer 21

Nipping of blood vessels and enlargement in other areas

Question 22

What can be seen in retinoscopy if malignant hypertension is present

Answer 22

Rupturing blood vessels and evidence of end organ damage.

Question 23

What is ischaemic heart disease

Answer 23

When the blood supply to the heart is insufficient for its metabolic demands. This can be deficient supply, excessive demand or both.

Question 24

What factors cause deficient supply of blood resulting in ischaemic heart disease

Answer 24

Coronary artery disease or reduced coronary artery perfusion as a result of shock or severe aortic valve stenosis.

Question 25

What factors cause excessive demand resulting in ischaemic heart disease

Answer 25

- Pressure overload, e.g. hypertension or valve disease. Pressure overload occurs due to a tight valve. - Volume overload, e.g. valve disease. Volume overload occurs due to a leaky valve.

Question 26

What level of occlusion leads to ischaemia in coronary heart disease

Answer 26

More than 75% occlusion.

Question 27

What is myocardial infarction

Answer 27

An area of necrosis of heart muscle resulting from reduction (usually sudden) in coronary blood supply.

Question 28

What are the causes of myocardial infarction

Answer 28

Coronary artery thrombosis, haemorrhage into a coronary plaque, increase in demand for oxygen in the presence of ischaemia.

Question 29

What are the clinical features of MI

Answer 29

Central "crushing" chest pain

Question 30

What can be used in the diagnosis of MI

Answer 30

ECG changes and blood markers

Question 31

What blood markers are tested for in MI

Answer 31

Enzymes such as creatine kinase and other proteins such as troponin. Troponin is used most often now as it is more sensitive to heart muscle changes.

Question 32

How long after an MI are changes observable in the heart muscle

Answer 32

About 24 hours. Less than 18 hours after there will be no changes.

Question 33

What are the macroscopic changes that occur between 24 and 48 hours after an MI

Answer 33

Pale, oedematous muscle

Question 34

What are the microscopic changes that occur between 24 and 48 hours after an MI

Answer 34

Odema, neutrophil infiltration and necrosis of myocytes

Question 35

What are the macroscopic changes that occur between 3 and 7 days after an MI

Answer 35

A yellow, rubbery centre with a haemorrhagic border

Question 36

What are the microscopic changes that occur between 3 and 7 days after an MI

Answer 36

Obvious necrosis and inflammation. Early granulation tissue.

Question 37

What are the macroscopic changes that occur between 1 and 3 weeks after an MI

Answer 37

The infarcted area is paler and thinner than the unaffected ventricle.

Question 38

What are the microscopic changes that occur between 1 and 3 weeks after an MI

Answer 38

Granulation tissue then progressive fibrosis.

Question 39

What are the macroscopic changes that occur between 3 and 6 weeks after MI

Answer 39

Silvery scar becoming tough and white

Question 40

What are the microscopic changes that occur between 3 and 6 weeks after MI

Answer 40

Dense fibrosis

Question 41

How can you identify which artery the occlusion occurred in

Answer 41

By the location of the infarct

Question 42

Where will the infarct be situated if the right coronary artery is occluded

Answer 42

On the inferior surface. it can involve the posterior septum.

Question 43

Where will the infarct be situated if the left coronary artery is obstructed

Answer 43

This is the artery of "sudden death". The infarct will be anterior.

Question 44

Where will the infarct be situated if the circumflex artery is obstructed

Answer 44

The infarct will be lateral.

Question 45

What are the complications of acute myocardial infarction

Answer 45

Sudden death, dysrhythmias, persistent pain, angina, cardiac failure, mitral incompetence, pericarditis, cardiac rupture, mural thrombosis, ventricular aneurysm.

Question 46

How does sudden death result from MI

Answer 46

The myocardial infarct can soften and rupture or ventricular fibrillation can occur.

Question 47

How do dysrhythmias result from MI

Answer 47

Due to abnormal electrical activity.

Question 48

How does persistent pain result from MI

Answer 48

Due to progressive necrosis

Question 49

How does angina result from MI

Answer 49

Ischaemia of non-infarcted cardiac muscle.

Question 50

How does cardiac failure result from MI

Answer 50

Due to ventricular dysfunction or dysrhythmias

Question 51

How does mitral incompetence result from MI

Answer 51

Due to papillary muscle dysfunction or necrosis

Question 52

How does pericarditis result from MI

Answer 52

The pericardium becomes inflamed which can cause sharp chest pain.

Question 53

How does cardiac rupture result from MI

Answer 53

Due to weakening of the cardiac wall by necrosis.

Question 54

How does mural thrombosis result from MI

Answer 54

Due to abnormal endothelial surface

Question 55

How does ventricular aneurysm result from MI

Answer 55

Due to the stretching of newly formed scar tissue.

Question 56

What is cardiac failure

Answer 56

Failure of the heart to pump sufficient blood to satisfy metabolic demands.

Question 57

What is the effect on the kidneys of heart failure

Answer 57

Under perfusion of the kidney leading to fluid retention and increased blood volume.

Question 58

What are the types of heart failure

Answer 58

Left heart failure, right heart failure, low output failure, high output failure, systolic failure, diastolic failure.

Question 59

What is cor pulmonale

Answer 59

This is right heart failure as a result of pulmonary hypertension

Question 60

What is acute heart failure

Answer 60

A rapid onset of symptoms often with a definable cause such as myocardial infarction.

Question 61

What is chronic heart failure

Answer 61

A slow onset of symptoms associated with ischaemic or valvular disease.

Question 62

What is congestive heart failure

Answer 62

Failure of both the right and left ventricles.

Question 63

What can cause high output heart failure

Answer 63

Thyroid disease.

Question 64

What can cause diastolic failure

Answer 64

The heart cannot relax properly. This can be due to TB.

Question 65

What is the most common cause of heart failure

Answer 65

A combination of hypertension and ischaemic heart disease.

Question 66

What are two examples of valvular heart disease

Answer 66

Bicuspid aortic valve and senile calcific stenosis.

Question 67

What is bicuspid aortic valve

Answer 67

Some people are born with a bicuspid as opposed to tricuspid aortic valve. This can lead to calcific stenosis at a younger age.

Question 68

What is senile calcific stenosis

Answer 68

Where there are lumps of calcification on the valve which stops it from opening or closing properly.

Question 69

What is the most common type of ventricular failure

Answer 69

Left ventricular failure

Question 70

What effect does left ventricular failure have on the pulmonary circulation

Answer 70

Pulmonary oedema and pulmonary hypertension

Question 71

How does right heart failure result from left heart failure

Answer 71

Left heart failure causes pulmonary hypertension which puts back pressure on the right ventricle and causes right ventricular failure.

Question 72

What are the clinical features of forward failure

Answer 72

Reduced perfusion of tissues. This is associated with advanced failure.

Question 73

What are the clinical features of backward failure

Answer 73

This results from increased venous pressure. For left ventricular failure backward failure results in pulmonary oedema. For right ventricular failure backward failure results in hepatic congestion and ankle oedema.

Question 74

What are the clinical features of left ventricular failure

Answer 74

- hypotension - pulmonary oedema - paroxysmal nocturnal dyspnoea (accumulation of fluid in the lungs at night meaning they wake up breathless) - breathlessness of exertion

Question 75

What are the clinical features of right ventricular failure

Answer 75

- ankle swelling | - hepatic congestion