Cardiac Pathophysiology

Question 1

With regards to atherosclerosis what causes the release of inflammatory cytokines and what does this lead to ?

Answer 1

Endothelial injury and dysfunction and Inflammation of endothelium

Question 2

What other issues does damage to the endothelium cause ?

Answer 2

Unable to prevent clots and loss of ability to adequately vasodilate

Question 3

What inflammatory cell adheres to the damaged endothelium what what does it release ?

Answer 3

Macrophages release enzymes and free radicals

Question 4

post macrophage adherence what causes further damage to the endothelium ?

Answer 4

Oxidation of LDLs

Question 5

Define hypertension

Answer 5

consistent elevation of systemic arterial BP:  Sustained elevation (140mmHg systolic or 90mmHg diastolic)

Question 6

What causes essential hypertension ?

Answer 6

Genetic factors and environmental factors

Question 7

What causes secondary hypertension ?

Answer 7

Altered hemodynamics, an underlying primary disease or can BP can be altered by drugs

Question 8

What affect does hypertension have on the eyes ?

Answer 8

Affects the micro-vascular circulation of the eye causing hypertensive retinopathy which may comprise of generalized and focal retinal arteriole narrowing

Question 9

What effect does hypertension have on the cerebral circulation ?

Answer 9

Increased pressure within the cerebral circulation may cause hemorrhage

Question 10

What effect does hypertension have on kidney function ?

Answer 10

Affects kidney perfusion and therefore causes Glomerular damage and ultimately kidney failure

Question 11

What does hypertension do to the ventricles within the heart ?

Answer 11

The increased myocardial work causes the left ventricle to hypertrophy which ultimately leads to heart failure

Question 12

Name 4 risk factors of coronary artery disease

Answer 12

1: Obesity
2: Hypertension
3: Hypercholesterolaemia
4: Diabetes

Question 13

Why do aortic aneurysms occur and what complications do the cause ?

Answer 13

There are many causes of AAA, peripheral vascular disease and hypertension are the two main causes.
PVD (PAD) is disease which causes narrowing and calcification of vessels and often this disease effects the aorta.
Hypertension causes the aorta to stretch and weaken causing an aneurysm.
This aortic aneurysm can rupture and cause major hemorrhage and blood loss and may cause death.

Question 14

Define stable angina

Answer 14

When a coronary artery is partially blocked, a patient may experience angina only on exertion and it will pass with rest.

Question 15

Define unstable angina

Answer 15

When a coronary artery is partially or fully blocked a patient may experience pain at rest which can lead to a myocardial infarction. This type of angina is most likely to lead to an MI.

Question 16

What is a STEMI ?

Answer 16

An ST elevated myocardial infarction, an ST elevation will be seen on an ECG and occurs when there is a full occlusion in a coronary artery also a plaque rupture can cause a STEMI as this rupture often fully occludes the coronary vessel.

Question 17

What does a STEMI lead to ?

Answer 17

Ischemia and infarction and ultimately death of cardiac tissue

Question 18

What is a NSTEMI ?

Answer 18

A non-ST elevated myocardial infarction. This is caused by a partial occlusion of a coronary artery. A NSTEMI can therefore lead to a STEMI as this partial occlusion is unstable and unpredictable.

Question 19

What is the Triad of Virchow and how does it explain the development of thrombi ?

Answer 19

1. Changes in the blood vessel wall
2. Changes in the blood constituents
3. Changes in the pattern of blood flow
   It is the these concepts that cause the development of a thrombus within a vessel as they underpin endothelial damage and turbulent flow.

Question 20

What is Peripheral arterial disease (PAD) ?

Answer 20

A condition usually caused by atherosclerosis in which disease causes stenosis (or occlusion) of arteries which prevents normal blood flow to the peripheries (usually the lower limbs are affected).

Question 21

What is Peripheral venous disease (PVD) ?

Answer 21

More specific than peripheral vascular disease where disease (atheroma) causes a narrowing of the veins in the peripheries (mostly legs but sometimes arms). PVD can also occur in lymphatic vessels causing lymphodema.

Question 22

What is deep vein thrombosis (DVT) ?

Answer 22

A form of venous insufficiency and a form of peripheral venous disease where a thrombus has occluded one of the deep veins in the legs resulting in local swelling and inflammation and localized edema.

Question 23

Define cardiac output

Answer 23

amount of blood pumped by heart per minute

Question 24

Use an equation to explain the relationship between CO, SV and HR

Answer 24

CO = SV multiplied by HR

Question 25

Define stroke volume

Answer 25

volume of blood per beat

Question 26

Define peripheral vascular resistance and what affects it

Answer 26

Radius of the vessel affects the PVR as does vessel compliance. This i the resistance that is must be overcome to push blood around the body

Question 27

What is pre-load (end diastolic volume/EDV)?

Answer 27

amount of blood stretching heart muscle at end of the filling phase (diastole).

Question 28

What is EDV determined by ?

Answer 28

The venous return to the heart. If there is more blood being returned to the heart there is more blood ejected therefore there will be an increase in stretch within the right ventricles which will cause a stringer contraction.

Question 29

What is after-load ?

Answer 29

This is referring to the ejection phase (systole) and the pressure which must be overcome within the ventricles in order to eject the blood.

Question 30

What is Cardiac reserve ?

Answer 30

ability of heart to increase output during increased activity

Question 31

Define Inotropy

Answer 31

contractile force of heart

Question 32

What is the pericardium and what is the term used to describe inflammation of the pericardium ?

Answer 32

The thin membrane surrounding the heart and pericarditis is where this membrane becomes inflammed

Question 33

What is a Pericardial effusion and what does this do to the heart's physiology ?

Answer 33

Serous fluid build up in the pericardial cavity making it harder for the heart to expand and beat efficiently which causes ventricles to constrict

Question 34

What are the three components of Beck's triad ?

Answer 34

1: Hypotension – heart can’t fill appropriately, cardiac output goes down 2: Muffled heart sounds 3: JVD d/t fluid backup

Question 35

What is endocarditis ?

Answer 35

infection of heart’s inner lining

Question 36

What is a mitral stenosis and what effect does this pathology have on the cardiovascular and pulmonary systems ?

Answer 36

A narrowing of the mitral valve which causes a build up of pressure within the LA. The LA then enlarges to compensate causing back-flow of pressure through the venous system to the lungs and causing subsequent build up of fluid within the lungs and the pulmonary circulation.

Question 37

What is mitral regurgitation ?

Answer 37

Where the valuve does not fully close between the LA and the LV therefore the LA enlarges and deforms causing electrical complications (Arrhythmia) and mechanical complications within the heart.

Question 38

What is aortic stenosis ?

Answer 38

A narrowing of the aortic valve. This caused increased pressure within the LV causing LV hypertrophy, as the LV gets stretched less blood is being pumped through the aorta and therefore after-load is decreased.

Question 39

What is aortic regurgitation ?

Answer 39

Were the aortic valve doesn't close fully allowing blood to regurgitate back into the LV. This again causes LV hypertrophy and subsequent LA hypertrophy which leads to pulmonary congestion and total HF.