Cardiology Flashcards
1
Q
Where does gas exchange occur in children and adults?
A
In the lungs.
2
Q
Where does fetal blood get oxygenated?
A
The placenta.
3
Q
How does fetal blood travel to the placenta?
A
Via the two umbilical arteries.
4
Q
From where do the umbilical arteries originate?
A
The internal iliac arteries.
5
Q
How does fetal blood return from the placenta to the fetus?
A
Via the umbilical vein.
6
Q
Name the three fetal shunts.
A
- Ductus venosus
- Foramen ovale
- Ductus arteriosus
7
Q
What does the ductus venosus connect?
A
The umbilical vein to the inferior vena cava.
8
Q
What is the function of the ductus venosus?
A
Allows blood to bypass the liver.
9
Q
What does the foramen ovale connect?
A
The right atrium with the left atrium.
10
Q
What is the function of the foramen ovale?
A
Allows blood to bypass the right ventricle and lungs.
11
Q
What does the ductus arteriosus connect?
A
The pulmonary artery with the aorta.
12
Q
What is the function of the ductus arteriosus?
A
Allows blood to bypass the lungs.
13
Q
What happens to the pulmonary vascular resistance after birth?
A
It decreases.
14
Q
What causes the functional closure of the foramen ovale at birth?
A
The left atrial pressure becomes greater than the right atrial pressure.
15
Q
What does the foramen ovale become after it is sealed shut?
A
The fossa ovalis.
16
Q
What are prostaglandins required for?
A
To keep the ductus arteriosus open.
17
Q
What causes the closure of the ductus arteriosus?
A
Increased blood oxygenation causes a drop in circulating prostaglandins.
18
Q
What does the ductus arteriosus become after closure?
A
The ligamentum arteriosum.
19
Q
What happens when blood stops circulating through the umbilical vein?
A
The ductus venosus stops functioning.
20
Q
What does the ductus venosus become after it closes structurally?
A
The ligamentum venosum.
21
Q
What are innocent murmurs also known as?
A
Flow murmurs
Innocent murmurs are very common in children.
22
Q
What causes innocent murmurs?
A
Fast blood flow during systole
Innocent murmurs typically occur in children due to increased blood flow.
23
Q
What are the typical features of innocent murmurs that begin with ‘S’?
A
- Soft
- Short
- Systolic
- Symptomless
- Situation dependent e.g. The murmur gets quieter with standing or only appears when the child is unwell.
24
Q
When may innocent murmurs not require further investigation?
A
When they have no concerning features
25
Suggest 4 features for a innocent murmur to be considered concerning?
* Louder than 2/6
* Associated symptoms e..g SOB, cyanosis
* Diastolic murmur
* Louder on standing
26
What are pan-systolic murmurs?
Murmurs occurring throughout the systolic contraction of the heart, between sounds 1 and 2.
27
What are common causes of pan-systolic murmurs in children?
* Mitral regurgitation
* Tricuspid regurgitation
* Ventricular septal defect
## Footnote
Each of these has specific locations where they are best heard.
28
What is the characteristic of ejection-systolic murmurs?
Crescendo-decrescendo character
## Footnote
They build and then fall in intensity with a peak in the middle.
29
What is a ejection- systolic murmur?
A murmur which occurs during systole, between the first and second heart sound.
30
What causes ejection-systolic murmurs in children?
* Aortic stenosis
* Pulmonary stenosis
* Hypertrophic obstructive cardiomyopathy
## Footnote
These murmurs are associated with specific heart conditions.
31
What causes the **second** heart sound?
The closure of the aortic and pulmonary valves.
32
What causes a **split** second heart sound?
Closure of the aortic and pulmonary valves at **different** times
## Footnote
This can occur normally during inspiration.
33
What is a **fixed** split second heart sound associated with?
Atrial septal defect
## Footnote
It does not vary during inspiration and expiration.
34
Explain why a atrial septal defect can cause a split second heart sound?
A Atrial septal defect allows blood to flow from left atrium to the right atrium, increasing the volume of blood the right ventricle has to empty **before** the pulmonary valve can close. This causes a ‘fixed split’ second heart sound.
35
What causes a **widely** split second heart sound?
Pulmonary valve stenosis
## Footnote
It takes longer for the right ventricle to empty through the narrowed valve.
36
Explain how pulmonary valve stenosis can cause a split second heart sound?
Pulmonary valve stenosis causes a ‘widely split’ second heart sound as it takes longer for the right ventricle to empty through the narrow pulmonary valve compared with the left ventricle.
37
What is the gold-standard investigation for diagnosing structural heart disease?
Echocardiogram
## Footnote
It provides detailed imaging of the heart's structure.
38
What additional investigations may be considered?
* ECG to diagnose arrhythmia
* Chest x-ray to diagnose other pathology
## Footnote
These can help in understanding symptoms related to heart issues.
39
What occurs during cyanosis?
Deoxygenated blood enters the systemic circulation, causing bluish-purple discolouration of the skin.
40
What is cyanotic heart disease?
Occurs when blood bypasses the pulmonary circulation and the lungs across a right-to-left shunt.
41
What is a right-to-left shunt?
A defect that allows blood to flow from the right side of the heart to the left side without travelling through the lungs.
42
List the heart defects that can cause a right-to-left shunt.
* Ventricular septal defect (VSD)
* Atrial septal defect (ASD)
* Patent ductus arteriosus (PDA)
* Transposition of the great arteries
43
Why are patients with VSD, ASD, or PDA usually not cyanotic?
Because the pressure in the left side of the heart is much greater than in the right side of the heart. Blood flows from an area of higher pressure to lower pressure, therefore preventing a right-to-left shunt.
44
What happens if pulmonary pressure increases beyond systemic pressure and there is a right to left shunt?
Blood will flow from right to left across the defect, causing cyanosis.
45
What is Eisenmenger syndrome?
A condition where increased pulmonary pressure leads to right-to-left shunting and cyanosis.
46
Do patients with transposition of the great arteries always have cyanosis?
Yes, they will always have cyanosis.
47
In transposition of the great arteries, where is the aorta attached?
The aorta is attached to the right ventricle.
48
Describe the blood flow in patients with transposition of the great arteries.
Blood drains from the systemic venous system (Inferior vena cava) into the right atrium and then the right ventricle, then out of the right ventricle into the aorta and systemic circulation, bypassing the lungs.
49
What does the ductus arteriosus connect?
The pulmonary artery with the aorta
50
When does the ductus arteriosus usually stop functioning?
Within three days of birth and it is entirely closed by 3 weeks.
51
What condition occurs when the ductus arteriosus fails to close after birth?
Patent ductus arteriosus (PDA)
52
What is a common association with patent ductus arteriosus?
Premature babies
53
Name a genetic condition that may be related to PDA.
Down syndrome
54
Name a maternal condition that may be related to PDA.
Diabetes or rubella
55
What may happen to a small PDA?
It may be asymptomatic and close spontaneously
56
What keeps the ductus arteriosus open during pregnancy?
Prostaglandin E2 produced by the placenta
57
What happens to prostaglandin E2 after birth?
It falls, resulting in closure of the ductus arteriosus
58
Describe the blood flow across a **Patent** Ductus Arteriosus.
**From the aorta to the pulmonary artery**
* The pressure in the aorta is higher than the pressure in the pulmonary vessels.
* Blood therefore flows across a PDA from the aorta to the pulmonary artery.
* It is a left to right shunt (blood from the left side of the heart crosses to the right side)
59
What type of shunt is created by a PDA?
Left-to-right shunt
60
As a result of a PDA, additional blood is returned to the right side, this increases the pressure in the pulmonary vessels.
What complication can arise due to increased blood in the pulmonary vessels?
Pulmonary hypertension
61
What is a consequence of pulmonary hypertension on the right ventricle?
Right ventricular hypertrophy
62
What leads to left ventricular hypertrophy in PDA?
Increased blood volume returning to the left side of the heart
63
What heart sounds may be present in a small PDA?
No abnormal heart sounds
64
What type of murmur is characteristic of larger PDAs?
Continuous crescendo-decrescendo 'machinery' murmur
65
Where is the 'machinery' murmur heard loudest?
Below the clavicle
66
What might a larger PDA present with?
Symptoms of shortness of breath, difficulty feeding, poor weight gain, lower respiratory tract infections
67
What confirms the diagnosis of PDA?
An echocardiogram
68
What medications may be used for medical closure of PDA in preterm infants?
Indomethacin, ibuprofen, or paracetamol
69
How do the medications for PDA closure work?
By inhibiting prostaglandins
70
What are the two surgical methods to achieve closure of a PDA?
* Endovascular procedures
* Open surgery
71
What treatment may be required for heart failure associated with PDA?
Diuretics
72
What is an atrial septal defect?
A defect (a hole) in the septum between the two atria, allowing blood to flow between them.
73
What are the two walls that grow across the gap between the atria during fetal development?
Septum primum and septum secundum.
74
What is the foramen ovale?
A small hole in the septum secundum that usually closes at birth.
75
What leads to the development of an atrial septal defect?
Defects in the septum primum or septum secundum.
76
What type of shunt occurs initially in an atrial septal defect?
Left-to-right shunt.
77
What happens as a result of increased flow to the right side of the heart due to an atrial septal defect?
Right-sided overload, increased pulmonary pressure, and right heart strain.
78
What condition develops when pulmonary pressure exceeds systemic pressure in the context of an atrial septal defect?
Right-to-left shunt and cyanosis.
AKA. **Eisenmenger Syndrome **
79
What is Eisenmenger syndrome?
The change to a right-to-left shunt with the development of cyanosis.
80
What are the types of atrial septal defects, from most to least common?
* Patent foramen ovale
* Ostium secundum
* Ostium primum.
81
What are some complications associated with atrial septal defects?
* Stroke
* Atrial fibrillation or flutter
* Pulmonary hypertension and right-sided heart failure
* Eisenmenger syndrome.
82
What unusual pathway does a clot take in patients with an ASD that may lead to a stroke?
The clot travels across the ASD, through the left side of the heart to the systemic circulation where it can then travel up to the brain and cause an ischaemic stroke.
83
What type of murmur is caused by atrial septal defects?
A mid-systolic, crescendo-decrescendo murmur loudest at the upper left sternal border.
84
What is a 'fixed split' second heart sound?
A split second heart sound that does not change with inspiration or expiration.
85
What are typical childhood symptoms of an atrial septal defect?
* Shortness of breath
* Difficulty feeding
* Poor weight gain
* Lower respiratory tract infections.
86
How is an atrial septal defect diagnosed?
An echocardiogram.
87
Who manages patients with an atrial septal defect?
A paediatric cardiologist.
88
What are the management options for an atrial septal defect?
* Active monitoring
* Percutaneous transvenous catheter closure
* Open-heart surgery.
