Cardiovascular 3.1 Flashcards
State examples of acyanotic defects
“Cyan” blue - cyanosis = blue
- Atrial septal defect
- Ventricular septal defect
- Parent foramen ovale
- Coarctation of aorta
- Parent ductus arteriosus
Diagram showing normal heart
Normal direction of blood flow
What is an atrial septal defect?
- Opening in septum between atria
(persists postnatally) (hole in wall)
EVEN THOUGH HOLE IN HEART, BLOOD PUMPED INTO SYSTEMIC CIRCULATION IS STILL OXYGENATED BECAUSE LEFT ATRIAL PRESSURE HIGHER THAN RIGHT - baby will not look blue - acyanotic defetc
Describe the direction of blood flow during atrial septal defects
Look at flow chart
BLOOD FROM LA to RA - medical term SHUNT.
Pressure builds RHS of heart, RA and RV
RA, RV overloaded with blood
Blood pumped to pulmonart artery to lungs
This leads to pulmonary vascular resistance (pulmonary capillaries cannot handle extra flow + pressure)
Blood cannot get past pulmonary capillaries, (like hitting a wall(
Leads to backwards flow, higher pressure builds up again into RHS of heart
Heart compensates over time, muscles of RHS of heart become stronger - hypertrophy
This can also lead to SHUNT REVERSAL (Eisenmenger syndrome). RHS pressure more than LHS pressure (now blood goes right to left due to pressure dynamics), this leads to deoxyganated blood to systemic circulation = cyanosis
Also, when all this extra blood vol passes pulmonary valce, it leads to delayed pulmonary valve closure (relative to closure of aortic valve), we can hear the delay - splitting of S2 Sound. Look at diagram, S1 ins a single line and S2 split into 2
Flow chat summary of what happens during ASD (atrial septal defect)
(focus on direction of blood flow and complications that occur)
3 main complications
If someone has an ASD and is on a long distance flight, which then causes them to develop a DVT, what are the comlications that can happen?
PARADOXICAL EMBOLISM
(embolism starts off RHS crosses over into left)
Common signs + symptoms of ASD
Pink - symptoms
Orange - Signs
What is a patent foramen ovale (PFO)?
oval shaped hole in septum between atria
(a bit like a flap valve, so not a type of ASD)
- Asymptomatic (LA pressure > RA, which maintains flap valve closure)
- If RA>LA, flap valve could open, causing blood to move from RA to LA If DVT occurs as well, paradoxical embolus.
State the most common congenital heart defect after PFOs
State 3 conditions VSDs are associated with
Ventricular Septal defect
Fetal alcohol syndrome
Chrosomal abnormalities: Down syndrome, Edwards Syndrome etc
What is a VSD?
Why is the condition acyanotic?
Ventricular Septum made of 2 components
1. Membranous Septum (located higher, more common site)
2. Muscolouus septum (lower, less common site for DST)
Acyanotic because LV pressure > RV pressure. Oxygenated Blood flows from LV > RV. Oxyganeted blood pymped systemically
Opening in septum between ventricles persists postnatally
Describe the direction of blood flow during ventricular septal defects
Look at flow chart
BLOOD FROM LV to RV - medical term SHUNT.
Pressure builds RHS of heart, RV
RV overloaded with blood
Blood pumped to pulmonart artery to lungs
This leads to pulmonary vascular resistance (pulmonary capillaries cannot handle extra flow + pressure)
Blood cannot get past pulmonary capillaries, (like hitting a wall(
Leads to backwards flow, higher pressure builds up again into RHS of heart
Heart compensates over time, muscles of RHS of heart become stronger - hypertrophy
This can also lead to SHUNT REVERSAL (Eisenmenger syndrome). RHS pressure more than LHS pressure (now blood goes right to left due to pressure dynamics), this leads to deoxyganated blood to systemic circulation = cyanosis
PAN-SYSTOLIC MURMUR
Flow chat summary of what happens during VSD (ventricular septal defect)
(focus on direction of blood flow and complications that occur)
3 main complications
Prolapse of aortic valve
Infective endocarditis - bacterial infection of heart
What are the symptoms of VSDs?
1) Small
2) Moderate
3) Large
Tachypnoea - babys breathing rapid
SYMPTOMS MOST COMMON IN CHILDHOOD
fatigue when feedling links to poor weight gain
What is a coarctation of aorta?
What are three conditions associated with this?
- Narrowing of aorta near site of Ductus Arteriosus (connection between pulmonary artery + aorta, should close after birth)
- Bicuspid aortive valve
VSD
Berry aneurysm
UNDERSTANDING: (The ductus arteriosus is a small blood vessel in babies before they are born. It connects two main arteries in the heart: the pulmonary artery (which goes to the lungs) and the aorta (which sends blood to the rest of the body). This connection allows blood to bypass the lungs since the baby gets oxygen from the mother’s placenta, not from breathing. After birth, when the baby starts breathing, the ductus arteriosus normally closes on its own because the lungs are now doing the job of getting oxygen. If it doesn’t close, it can cause problems and may need medical treatment.)
What are the three types of coarctation of aorta?
- Ductal coarctation (at site of PDA)
- Preductal coarctation (before PDA)
- Postductal coarctation (after PDA)
(Understanding: Coarctation of aorta: 3 areas of narrowing. If we get narrowing, extra blood flow, against restricted vasculatur, build up pressure. We have left ventricle pumping blood at high pressure. As soon as it comes out of aorta, there is a narrowing. Leads to pressure build up, so ppl with this condition can have hypertension )
Therefore, COARCTATION OF AORTA LEADS TO
1. Hypertension
2. Re-coarctation after repair
3. Right and left ventricular hypertrophy = congestive heart failure (Understanding: high pressure trying to go into narrow gap, blood goes back, backflow of pressure, into LV, LV compensates, builds up more muscular walls. )
Septal defects can cause systolic heart murmurs. How can you tell a systolic heart murmur from a diastolic one?
State signs and symptoms present in patients with coarctation of aorta
- Chest pain
- Intermittent leg claudication
What is a patent ductus arteriosus?
State 3 risk factors for PDA
- Occurs in 5-10% of congential heart defects
- Ductus arteriosus does not close after birth
- Causes oxygenated blood to flow backwards from aorta into lungs instead of going to rest of body - Genetic syndromes (trisomy 21)
Rubella infection during pregnancy
Valporate use during pregnancy
Birth at high altitude (exposure to low oxygen tension)
Ductus arteriosus closes 12-18 hours after birth
Pressure in aorta > pulmonary artery, flow of blood into pulmonary artery from aorta. Oxygenated blood to systemic circulation.
What complications are involved with PDA?
Extra blood into pulmonary artery.
More strain on pulmonary capillaries. Same chain of events = pulmonary hypertenstion = right ventricular hypertophy, congestive heart failure
RESPIRATORY DISTRESS SYNDROME
What signs and symptoms would a PDA patient present with?
Small PDA and moderate/large PDA
Symptoms in childhood.
State 4 examples of cyanotic defects
- Tetralogy of fallot (4 main features of this condition, tetra)
- Tricuspid atresia
- Transposition of great arteries
- Hypoplastic left heart
What are the 4 features of tetralogy of fallot? (PROVe)
FOCUS ON DIRECTION OF BLOOD FLOW
- Pulmonary stenosis - narrowed pulmonary valve
- Right ventricular hypertrophy - due to above
- overriding aorta (aorta sits on top of VSD, due to hole in Ventricles, recieves blood from both ventricles - aorta starts to receieve deoxyganeted blood)
4, Ventricular septal defect (right to left shunt)
State signs and symptoms of Tetralogy of Fallot
Sqautting to rest when exercising. Improves oxygenation
State 4 major complications which occur as a result of tetralogy of fallot
regurgitation relates to leaky valves
Aortic root dilation (aortic root gets bigger due to increase in pressure)
What is tricuspid atresia?
Complete absence of tricuspid valve (atresia means absence)
No flow of blood from RA to RV
Babies who have this and manage to survive, have some sort of hole in heart (PFO, ASD etc), so blood ends up going from RA to LA
So, deoxyganated blood into LV, into aorta, into systemic circulation
RV becomes hypoplastic. Both ventricles look like one big ventricle, as you can see in diagram
State signs and symptoms of tricuspid atresia
1) What is transposition of the great arteries?
2) In what circumstance can a baby suffering with transposition of great arteries survive?
CLARIFY WITH HIFZA
great arteries - aorta, pulmonary artery, “transpose” = switch
Aorta which normally comes from LV is coming from RV
Pulmonary artery normally comes from RV is coming from LV
TWO PARALLEL CIRCUITS rather than one circulation in series.
2) not compatible with life unless shunt maintained after birth (through PDA, ASD, VSD)
State signs and symptoms of hypoplastic left heart
