Cardiovascular System

Question 1

pericarditis

Answer 1

inflammation of pericardium causing chest pain, may also may serous membrane rough

a seriously inflamed pericardium may calcify, reducing cardiac efficiency severely

Question 2

pericardial effusion

Answer 2

caused by some inflammatory diseases, it is the passage of fluid from pericardial capillaries into pericardial cavity/accumulation of pus

heart becomes compressed and ineffective

Question 3

what are heart murmurs?

Answer 3

the turbulent flow of blood caused by a) narrowed valve - stenosis a/o b) valve not closing properly - incompetence

these occur when blood flow is the highest, so we can predict where in the cardiac cycle they occur

eg aortic stenosis produces murmurs during aortic ejection phase

Question 4

aetiology of congenital heart diseases

Answer 4

genetic eg Down’s, Turner’s, Marfan’s syndrome, or polygenic

environmental eg teratogenicity from drugs, alcohols

maternal infections eg rubella, toxoplasmosis

Question 5

cyanosis, acyanosis

Answer 5

cyanosis: presence of deoxygenated Hb in arterial circulation, normally due to right to left shunt

eg Tetralogy of Fallot, (VSD/pulmonary stenosis)

acyanosis: heart defect but with normal (~100%) levels of oxygenated blood in arterial circulation, normally due to left to right shunt

eg ASD, VSD, PDA

Question 6

atrial septal defects

Answer 6

increased pulmonary blood flow

RV volume overload

eventual right heart failure

no pulmonary hypertension

Question 7

ventricular septal defects

Answer 7

most common place is by a/v valves, but can also occur at the bottom

left to right shunt

RV overload

eventual pulmonary hypertension

Question 8

aortic stenosis

Answer 8

valve is thick, turbulent blood flow, ventricle is very thick

eventually coronary blood supply will be insufficient to supply the enlarged heart

treated by stretching/replacing the valves

Question 9

coarctation of aorta

Answer 9

narrowing of the aorta in the region of the ligamentum arteriosum (remnant of ductus arteriosus)

this increases the afterload on left ventricle possibly leading to l ventricle hypertrophy

does not affect head and u/limbs, as their vessels normally emerge proximal to the ligamentum arteriosum

range of severity from severe (present at birth) to mild (detected as an adult)

can use a stent in adults, but in babies this usually means the baby won’t grow particularly well->will have coarctation in later life

Question 10

tetralogy of fallot

Answer 10

outflow is rotated clockwise so aorta sits halfway between l and r ventricles so septum cannot close->sub aortic ventricular septal defect

so there is not enough space for the pulmonary artery-> tetralogy:

1 pulmonary stenosis

2 ventricular septal defects

3 r/ventricular hypertrophy

4 over-riding aorta

1) causes R -> L shunting in ventricles as the pressure in the r ventricle increases to deal w/ the stenosis

Question 11

tricuspid atresia

Answer 11

no way through tricuspid valves

there must therefore be a complete r to l shunt of all the blood returning to the right atrium (ASD/PFO) and a VSD or PDA to allow blood flow to the lungs

this is incurable as valves cannot be inserted, but can be treated

Question 12

patent foramen ovale

Answer 12

20% of population

generally silent as l pressure > r pressure causes functional closing of flap valve

however it may be the route that a venous embolism takes to reach the systemic circulation if the pressure on the r side of the heart increases transiently

Question 13

PDA

Answer 13

patent ductus arteriosus

failure of ductus arteriosus to close, causing blood flow from aorta to pulmonary artery after birth (ie the other way round that occurs in foetuses, from high to low pressure)

Question 14

transposition of great arteries

Answer 14

results in two unconnected parallel circulations instead of two circulations in series

r ventricle -> aorta and l ventricle -> pulmonary trunk

not compatible w/ life after birth UNLESS a shunt exists to allow the two circulations to communicate eg PDA or ASD

Question 15

hypoplastic left heart

Answer 15

left ventricle is underdeveloped, ascending aorta v small, right ventricle supports the systemic circulation instead, must be a r to l shunt after birth ie ASD and PDA

prostaglandin can be given, keeping the ducts open and maintaining foetal circulation after birth, buying time, we can now reconstruct the entire aorta using pulmonary artery, use right ventricle to pump blood round the systemic circulation

systemic veins directly to pulmonary circulation

Question 16

pulmonary atresia

Answer 16

no r ventricle outlet ie pulmonary artery is closed

r to l atrial shunt of entire venous return

blood flow to lungs via PDA -> prostaglandin is necessary to keep these valves open