Week 1 - Coronary Artery Disease

Question 1

Why do we need the cardiovascular system (3 things)

Answer 1

1. Rapid transport of nutrients to tissue
3. Rapid removal of metabolic waste from tissues

Question 2

What are the 3 coronary arteries called

Answer 2

Right coronary artery, left anterior descending coronary artery, Left circumflex coronary artery

Question 3

What is the main way of increasing oxygen supply to the heart during exercise

Answer 3

Metabolic hyperaemia

Question 4

Define cardiac output (CO)

Answer 4

The volume of blood ejected by 1 ventricle in 1 minute

Question 5

Define stroke volume

Answer 5

The volume of blood ejected from the ventricle in systole

Question 6

What is typical cardiac output during rest

Answer 6

5L/min

Question 7

What is preload in the intact heart?

Answer 7

The stretch on the ventricular fibres just before contraction (ie at the end of diastole)

Question 8

What is starlings law

Answer 8

The greater the Preload
the greater the force of contraction the greater the stroke volume

Question 9

How do you measure RV preload pressure

Answer 9

CVP (central venous pressure) determines RV (right ventricular) preload

Question 10

Why is starlings law important

Answer 10

To balance the outputs of the RV and LV
… therefore contributes to increased SV during upright exercise. - Causes a fall in CO during standing - postural hypotension - dizziness

Question 11

Define Afterload

Answer 11

Afterload can be thought of as the resistance the heart must overcome to eject its contents

Question 12

What is tachycardia

Answer 12

Increased sympathetic activity

Question 13

Bradycardia

Answer 13

Increased parasympathetic activity

Question 14

What is the flow to cardiac output equation

Answer 14

Flow = ^pressure/resistance

Question 15

What are the 2 inflow valves of the heart

Answer 15

Tricuspid val;ve, mitral valve

Question 16

What are the 2 outflow valves

Answer 16

Aortic valve and pulmonary valvue

Question 17

What are the 2 issues that can happen to valves

Answer 17

Stenosis and regurgitation

Question 18

Which are the valves most commonly affected

Answer 18

Mitral and aortic valves

Question 19

What are common causes of regurge

Answer 19

Ischaemia heart disease
Hypertension
Cystic Medial Necrosis (age)
Aortic dissection
bicuspid aortic valve

Question 20

How does valve disease present

Answer 20

Incidental finding - ECHO, murmur
Heart failure symptoms - breathless, fatigue, peripheral oedema

Mitral valve disease - atrial fibrillation (AF), stroke
Aortic valve disease - angina, dizziness, sudden death

Question 21

What causes mitral stenosis

Answer 21

Commisural fusion

Question 22

How does rheumatic fever cause MS

Answer 22

Leaflet thickening so MS valve is <2cm. Due to commisural fusion

Question 23

What is the pathophysiology of MS

Answer 23

Increase pressure and volume in the LA
So there is a backlog of blood increasing pulmonary pressures and right heart pressures
Less blood out of LA to LV
So LA dilates (gets bigger) - giving rise to AF
Therefore reduced cardiac output

Question 24

What are the 4 classic findings of MS

Answer 24

Increased in heart sound (S1)
Hear opening snap - when mitral opens
Mid diastolic murmur
Pre-systolic accentuation

Question 25

How do you treat MS (mitral stenosis)

Answer 25

Balloon angioplasty - a catheter into the vein and push up to the heart and over the mitral valve then inflat the balloon

Question 26

That is the pathophysiology of mitral regurgitation

Answer 26

Valve should be closed in systoli - but it isn’t Pan systolic murmur LA dilates as blood flows back to it Predisposing to AF In the LV - reduced stroke volume as there is 2 ways for the blood to go Reduced cardiac output Frank-starling mechanism can compensate to increase preload and stroke volume but this cannot continue over time

Question 27

What is the most common cause of MV regurge

Answer 27

MV prolapse

Question 28

What are the 3 causes of aortic stenosis

Answer 28

Calcific - age Bicuspid Rheumatic fever

Question 29

Pathophysiology of AS

Answer 29

Thickening of aortic valve cause obstruction to outflow Pressure gradient develops across the valve and turbulent flow causes a load murmur in systole. LV is pressure loaded because of obstruction to flow and hypertrophies

Question 30

What are the symptoms of aortic stenosis

Answer 30

SOB on exertion Exertion all dizziness and syncope Aortic murmur and angina

Question 31

How do you calculate coronary percussion pressure

Answer 31

Coronary percussion pressure = Aortic diastolic pressure - left ventricular end-diastolic pressure (LVEDP)

Question 32

Aortic regurgitation

Answer 32

Blood flows back in diastole - blood goes back to LV rather than round the body Less aortic diastolic pressure Less Coronary perfusion pressure Less myocardial O2 supply (angina) LV dilates and hypertrophy Have a collating pulse - increased JVP

Question 33

Risk factors for Coronary heart disease

Answer 33

Male, smoke, obesity, hypertension, high cholesterol, alcohol, stress, sedentary lifestyle, diet, age, ethnicity, family history

Question 34

What are the risk calculators for Coronary heart disease

Answer 34

Framingham Risk Score QRISK3

Question 35

What are some secondary prevention methods to stop Coronary heart disease

Answer 35

Anti-platelets (Aspirin, Clopidogrel, Prasugrel, Ticagrelor), Beta Blockers / Ivabradine, Statin, ACEi, Lifestyle modification, Psychosocial factors, Cardiac Rehabilitation