(cardioresp) structural heart disease

Question 1

what is the tricuspid valve?

Answer 1

the valve that allows blood to flow from the right atrium to the right ventricle

prevents blood from flowing backward

Question 2

where is the tricuspid valve found?

Answer 2

attached to the walls of the right ventricles via the chordae tendinae (three cusps)

Question 3

what is the mitral valve?

Answer 3

the valve that allows blood to flow from the left atrium to the left ventricle

prevents blood from flowing backward

Question 4

where is the mitral valve found?

Answer 4

attached to the walls of the left ventricles via the chordae tendinae (two cusps)

Question 5

how many cusps does the tricuspid valve have?

Answer 5

three

Question 6

how many cusps does the mitral valve have?

Answer 6

two

Question 7

what are the semi-lunar valves?

Answer 7

pulmonary valve (right ventricle)

atrial valve (left ventricle)

Question 8

when does blood move past the semi-lunar valves?

Answer 8

when the ventricles contract, blood is pushed past the semi-lunar valves to either the lungs for oxygenation OR to the rest of the body

Question 9

what is the heart made up of?

Answer 9

myocardium

Question 10

what are the layers of the heart?

Answer 10

epicardium (epithelial cells)
myocardium
endocardium

Question 11

define systole

Answer 11

contraction

Question 12

define diastole

Answer 12

relaxation

Question 13

what are the two main categories of structural heart disease?

Answer 13

congenital (from birth)

acquired (happen later in life)

Question 14

what are examples of congenital structural heart diseases?

Answer 14

atrial septal defect (ASD)

ventricular septal defect (VSD)

coarctation of aorta (part of the aorta being narrower)

patent foramen ovale (PFO - opening bw two atria in atrial septum)

patent ductus arteriosus (extra blood vessel between aorta and pulmonary artery)

tetralogy of fallot (TFO)

Question 15

what are examples of acquired structural heart diseases?

Answer 15

valvular dysfunctions (atrial/mitral stenosis or regurgitation)

cardiomyopathies

Question 16

what is ventricular septal defect?

Answer 16

wall between two ventricles fails to develop properly so mixing of oxygenated and deoxygenated blood

Question 17

how does ventricular septal defect present?

Answer 17

poor weight gain, palpitations, poor feeding

Question 18

how is ventricular septal defect treated?

Answer 18

either if hole is small enough = closes on its own

OR

cardiac catherisation/open heart surgery

Question 19

what are the congenital defects in TFO?

Answer 19

tetralogy of Fallot

1) ventral septal defect (VSD)
2) pulmonary valve stenosis
3) misplaced aorta
4) right ventricular hypertrophy

Question 20

what is atrial septal defect?

Answer 20

hole in the septum between the atria

can occur during embryonic development if the two atria fail to develop properly

Question 21

what is coarctation of the aorta?

Answer 21

narrowing of wall of aorta SO blood has to force through a narrower exit

= so ventricle has to work harder to push blood out to the rest of the body (can lead to LVH)

Question 22

which heart valves are most commonly affected by stenosis or regurgitation?

Answer 22

aortic valve (1)

mitral valve

Question 23

define stenosis

Answer 23

narrowing

Question 24

define regurgitation

Answer 24

incompetence leading to backflow

Question 25

what is the most common valvular disease requiring treatment?

Answer 25

aortic stenosis | second most frequent cause of cardiac surgery

Question 26

what precedes aortic stenosis?

Answer 26

aortic sclerosis = aortic valve thickening without flow limitation

Question 27

what is aortic stenosis?

Answer 27

narrowing of the aortic valve

Question 28

how is aortic stenosis suspected?

Answer 28

auscultating heart of patient = early-peaking, shrill, systolic ejection murmur confirmed by echocardiography

Question 29

why does aortic stenosis cause an early-peaking systolic ejection murmur?

Answer 29

due to aortic sclerosis (thickening of the aortic valve)

Question 30

what are the causes of aortic stenosis?

Answer 30

rheumatic heart disease congenital heart disease calcium build-up (age-related)

Question 31

what are the risk factors for aortic stenosis?

Answer 31

hypertension high LDL levels smoking elevated CRP congenital bicuspid valves (aortic valves have two instead of three cusps) CKD radiotherapy old age

Question 32

what is bicuspid aortic valve disease and why is it a risk factor for aortic stenosis?

Answer 32

instead of having three cusps, the aortic valve has two cusps ``` 1 = automatic narrowing (stenosis) of the aortic valve 2 = more prone to wear and tear and infection (can lead to stenosis) ``` (can also cause aortic regurgitation)

Question 33

describe the pathophysiology of aortic stenosis

Answer 33

abnormal blood flow across the valve (e.g. due to bicuspid aortic valve) OR an unknown trigger = vascular endothelium is damaged = endocardial injury = inflammatory process initiated (similar to atherosclerosis) = leaflet fibrosis + deposition of calcium on the valve = progressive fibrosis and calcium deposition limit aortic leaflet mobility = aortic stenosis

Question 34

describe the pathophysiology of aortic stenosis caused by rheumatic disease

Answer 34

Streptococcus infection targets the valvular endothelium = autoimmune inflammatory reaction = calcification = limits aortic leaflet mobility = aortic stenosis

Question 35

what is rheumatic heart disease?

Answer 35

rheumatic heart disease starts as a sore throat from a bacterium called Streptococcus pyogenes sometimes = repeated strep infections = cause the immune system to react against the tissues of the body i.e. inflaming and scarring the heart valves = rheumatic fever (so rheumatic heart disease results then from the inflammation and scarring of heart valves caused by rheumatic fever)

Question 36

what is rheumatic fever?

Answer 36

when there are repeated strep infections cauing the body to produce an immune response against the body's own tissues = inflammation + scarring of the heart valves

Question 37

what are the complications of untreated or poorly managed aortic stenosis?

Answer 37

left ventricular hypertrophy systolic heart failure

Question 38

how does aortic stenosis lead to left ventricular hypertrophy?

Answer 38

aortic stenosis blocks left ventricular outflow the left ventricle needs to generate excess pressure to pump out sufficient amounts of blood afterload increases heart responds by increasing muscle muscle to allow the increased pressure requirements to be met = LVH

Question 39

how does left ventricular hypertrophy lead to systolic heart failure?

Answer 39

long-standing, increased afterload = LVH if aortic stenosis continues to worsen after this = still increased afterload = adaptive mechanism of LVH fails = left ventricular wall stress increases LVW stress increase causes systolic function to decline = systolic heart failure