General

Question 1

Give 4 risk factors which predispose someone to an MI.

Answer 1

Diabetes
Obesity
Smoking
Age
Stress
Hypercholestrolaemia
Hypertension
Family history of IHD

Question 2

Give two ways statins act to reduce blood cholesterol levels.

Answer 2

Inhibition of HMG-CoA reductase - thus suppressing endogenous cholesterol production.

Up regulate LDL receptors (on liver, LDL taken in and converted to bile salts), thus removing LDL from blood.

Question 3

What is an end artery?

Answer 3

An end artery is a terminal artery supplying all or most of the blood to a section of tissue without significant collateral circulation.

Question 4

What colour infarct is associated with occlusion of an end artery? Give an example of an organ where you would expect to find this.

Answer 4

White infarct.

Kidney

Question 5

What is meant by the term cardiac tamponade?

Answer 5

Fluid accumulating in the pericardium. Leads to impaired ventricular filling and reduced cardiac output.

Question 6

What is pericarditis?

Answer 6

Pericarditis is an inflammation of the pericardium leading to sharp substernal chest pain that radiates to the back, and that is aggravated by movement and respiration.

Question 7

What is a pericardial effusion?

Answer 7

Pericardial effusion is an accumulation of fluid in the pericardial cavity. The effusion collects in the closed cavity and causes distention. When the pericardium cannot distend any more, abnormally high pressures build up and cardiac tamponade results.

Question 8

What is cardiac tamponade?

Answer 8

Impaired ventricular filling leading to loss of cardiac output.

Question 9

What is the cardiac output at rest in an average 70kg male?

Answer 9

5L/min-3

Question 10

What is the cardiac output during intense exercise?

Answer 10

The cardiac output can rise to 25L/min-3

Question 11

What structure forms the right border of the heart?

Answer 11

Right atrium

Question 12

What forms the left border of the heart?

Answer 12

Left ventricle

Question 13

What is meant by the term cardiac tamponade?

Answer 13

Fluid accumulates in the pericardium which compresses the heart.

Question 14

What treatment is there for a cardiac tamponade?

Answer 14

Pericardiocentesis

Question 15

What area of the heart does the left coronary artery supply?

Answer 15

Supplies anterior aspect of left ventricle and some of right, also inter ventricular septum.

Question 16

What typical symptom is experienced by a patient with an MI?

Answer 16

Crushing chest pain that may radiate to the arm and neck.

Question 17

Describe, precisely, the spread of excitation that occurs in the heart.

Answer 17

SAN initiates action potential which travels to surrounding myocytes over the atria and up the walls of the atria to cause atrial systole.
Excitation then spreads to the AVN where there is a delay (120ms).
Electrical excitation then spreads down the ventricular septum (L and R bundle of His) then Purkinje fibres spreading up the walls of the ventricles (from endocardium to epicardium) to cause ventricular systole.

Question 18

What is cardiac output?

Answer 18

The product of stroke volume and heart rate.