Embryology + Congenital + Inherited Flashcards
1
Q
what is the function of the placenta
A
Fetal homeostasis Gas exchange Acid base balance Nutrient transport to fetus Waste product transport from fetus Hormone production Transport of IgG produces PGE2 (prostaglandin E2)
2
Q
describe the lungs in utero
A
fluid filled and unexpanded
3
Q
what is the role of the pulmonary circulation in utero
A
to supply the lungs with what it needs to grow and develop
4
Q
what is the role of the liver and gut
A
liver little role in nutrition and waste management
gut not in use
5
Q
where does the foetal heart pump blood to
A
the placenta via the umbilical arteries
6
Q
from what arteries do the umbilical arteries arise from
A
illiac arteries
7
Q
where does blood from the placenta travel to
A
to the foetus via the umbilical vein
8
Q
where does the oxygenated blood from the placenta return to in the heart and what is its role
A
right side of the heart, to be distributed around the heart to the growing foetus
9
Q
why is the pulmonary resistance in utero so high
A
as lungs collapsed
10
Q
what are shunts and why are they needed
A
as pulmonary circulation very high resistance the vessels cant deal with all the blood, shunts are passage ways that allow most of the blood supply to bypass the lungs
11
Q
what are the 3 shunts in foetal circulation
A
ductus venosus,
foramen ovale,
ductus arteriosus,
12
Q
what is the role of the ductus venosus
A
connects the umbilical vein to the vena cava, allowing the blood from the placenta to bypass the liver
13
Q
what is the foramen ovale and what is its role
A
opening in atrial septum connecting RA to LA allowing passage of blood between sides of the circulation
14
Q
what is the role of the ductus arteriosus
A
connects pulmonary bifurcation to the descending aorta
15
Q
what is the name of the liver circulation and what is it bypassed by, and why
A
portal circulation
bypassed by ductus venosus
as nutrients from placenta don’t need further processing in liver
16
Q
why is the mixing of blood facilitated by the foramen ovale so important
A
as allows the best oxygenated blood to enter left atrium then on to LV where it goes to ascending aorta and carotids, supplying the development of the foetus
17
Q
on which side is the membrane flap of the foramen ovale on
A
left atrium side
18
Q
how is foetal circulation opposite to adult circulation
A
pressure in right atrium and pulmonary circulation much higher than left side- (because of collapsed lungs) allows blood to flow through foramen ovale
19
Q
how much of RV output goes to lungs and why
A
7% as pressure do high, rest taken by ductus arteriosus to descending aorta
20
Q
how is the patency of the ductus arteriosus maintained
A
by circulating prostagladin E2
21
Q
what happens to the lungs in the first few minutes following birth
A
baby initially low sats (60%)
baby inflates lungs by crying (lung fluid goes into amniotic fluid)
baby goes from blue to pink
22
Q
what happens to the Pulmonary vascular resistance after birth and how
A
lungs expand, increase in circulating oxygen-
relaxes smooth muscles of lungs = resistance decreases= cardiac output to lungs increases
23
Q
what happens to systemic vascular resistance after birth
A
cord clamped and cut, placenta gone, resistance to flow in systemic system rises
24
Q
what do the changes in circulation following birth lead to
A
closure of the foramen ovale and constriction and closure of the ductus arteriosus
25
what causes the foramen ovale to close
fall in P(ulmonary) VR and rise in SVR= increases the LA pressure, making it exceed to RA pressure pushing the membrane flap shut
26
what causes duct constriction
```
increased pO2 (only place in body that O2 causes vasoconstriction)
decreased blood flow (decrease pulmonary vascular resistance)
decreased prostaglandins (placenta removed)
```
27
when does the ductus arteriosus close and what does it form
functional closure first hours/days
anatomical closure 7-10 days
forms the fibrous ligament- ligamentum arteriosum
28
what can a patent ductus arteriosus lead to in peterm infants
excessive blood in ling circulation and not enough blood in brain and gut
29
what are the treatment options for a patent ductus arteriosus
'wait and see', NSAIDs (inhibit prostaglandin production to help constrict the duct),
surgery
30
what is the treatment for a duct dependant circulation
IV prostaglandin E2 can keep duct open until an alternative shunt established/ definitive surgery carried out
31
when does pulmonary resistance reach a normal level
drops after birth until 2-3 months
32
in what conditions is persistent pulmonary hypertension more common in newborns
```
sepsis,
hypoxic ischaemic insult,
meconium aspiration syndrome,
cold stress,
anatomical abnormality (e.g. congenital diaphragmatic hernia)
```
33
what physiological failures can cause persistence of pulmonary hypertension in a newborn
patent foramen ovale or ductus arteriolus
34
what are the symptoms of persistent pulmonary hypertension in newborns
blue baby, large difference between pre and post ductal oxygen saturation
35
how is PPHN treated
ventilation, oxygenation, high systemic blood pressure, inhaled nitric oxide (will drop vasculature pressure), ECLS (extracorporeal membrane oxygenation (ECMO))
36
where is pre and post ductal saturation measured
pre hands (80%), post feet (60%)
37
what is congenital heart disease
abnormality of the structure of the heart (doesnt include cardiomyopathy or arrhythmias that present later)
“a gross structural abnormality of the heart or intrathoracic great vessels that is actually or potentially of functional significance.”
38
when do congenital heart diseases present
at birth
39
what is the incidence of congenital heart disease
between 1-13 per 1000 live births
40
what is the spectrum of severity of congenital heart diseases
mild, moderate, severe and major
41
describe mild heart disease
asymptomatic- may resolve spontaneously or may progress to moderate of severe in adulthood
42
describe moderate congenital heart disease
require specialist intervention and monitoring in cardiac centre
43
describe severe congenital heart disease
present severely ill/ die in newborn period or early infancy
44
describe major congenital heart disease
requires surgery within the first year of life
45
give examples of mild Congenital HD and how they can progress
Small VSD, PFO / small ASD, small PDA. Bicuspid aortic valve may progress in adulthood to severe AS or AR and need surgery
46
give examples of moderate congenital HD
mild or moderate AS, PS. larger or complex ASD, VSD
47
give examples of severe congenital heart disease
cyanotic lesions, all duct dependant lesions, truncus
48
how does congenital heart disease present
screening: antenatal, newborn baby check
well baby with clinical signs- murmur
unwell baby with- cyanosis, shock, cardiac failure due to low CO
49
what signs are seen in congenital heart disease when presenting soon after birth
cyanosis
50
what signs are seen in congenital heart disease when presenting at the day 1-2 baby check
murmurs, abnormal pulses, cyanosis
51
what signs are seen in congenital heart disease when presenting 3-7 days after birth
sudden circulatory collapse, shock, cyanosis, sudden death
52
what signs are seen in congenital heart disease when presenting at 4-6 weeks
what signs are seen in congenital heart disease when presenting soon after birth
53
what signs are seen in congenital heart disease when presenting at 6-8 weeks
incidental finding of murmurs
54
why causes blue baby/ cyanosis
any condition that causes deoxygenated blood to bypass the lungs and enter the systemic circulation /
mixed oxygenated and deoxygenated blood enters the systemic circulation from the heart
55
what are the differential diagnosis' of cyanosis in newborns
cardiac disease, respiratory disease, persistent pulmonary hypertension
56
what is the most common cyanotic condition
transposition of great arteries
57
why does transposition of the great arteries cause acidosis
as babies unable to perform anaerobic metabolism and builds up lactic acod
58
what happens when a duct closes in a baby who has duct dependent circulation
collapse, severe cyanosis or pallor, tachypnoea, distress, grunting, rapid deterioration, death
59
what are the clinical signs of duct closure
pallor, prolonged CRT, poor or absent pulses, hepatomegaly, crepitations, increased work of breathing, profoundly acidotic
60
how is duct closure treated
ABC, prostaglandin E2 to reopen duct, surgery
61
what are the two types of duct dependent conditions
duct dependent systemic circulation (physical obstruction to blood getting to left side of the heart)
duct dependent pulmonary circulation (right side of heart)
62
what can cause duct dependent systemic circulation (left side of the heart)
hypoplastic left heart,
critical aortic stenosis,
interrupted aortic arch,
critical coarctation of aorta
63
what can cause duct dependent pulmonary circulation (right side)
tricuspid atresia,
pulmonary atresia
(complete blockage)
64
describe hypoplastic left heart syndrome
underdeveloped left heart- very small LV< mitral valve and ascending aorta= mixed blood in right side, PA and AO. no palpable pulse and increasingly acidotic
65
what does pulmonary atresia result in
retrograde filling of PA via ductus arteriosus. No VR output, associated with VSD, circulation to lungs via aorta
66
what can cause a presentation of heart failure
large right to left shunts (increased pulmonary load) e.g large VSD
67
when does cardiac failure present in neonates
after a few weeks as pulmonary pressure drops
68
what are the clinical signs of heart failure in babies
```
Failure to thrive
Slow / reduced feeding
Breathlessness (especially when feeding)
Sweatiness
Hepatomegaly
Crepitations
```
69
when does a VSD murmur develop
as pulmonary pressure drops over first weeks
70
why does VSD lead to congestive heart failure
as increases pulmonary circulation and work load in right ventricle
71
how is CCF treated in babies
diuretics and high calorie formula to help baby grow before surgery
72
what is the long term management for major congenital heart disease
surgery, further interventions for developmental problems, hypoxia, further surgery, emotional/ social issues
73
what is a patent ductus arteriosus repaired
catheter procedure, in through femoral vein to the heart
74
how is a hypoplastic left heart treated
3 stage complex surgery, RV will fail over time, need transplant
75
what mutations can cause inherited cardiac problems
on genes that encode cardiac muscle or ion channels of the heart
76
what are the two forms of arrhythmogenic inherited cardiac conditions
channelopathies (arrhythmogenesis is related to an ion current imbalance) and cardiomyopathies (arrhythmogenesis related to scar/ electrical barrier formation and subsequent re entry)
77
name two inherited channelopathies
congenital long QT syndrome, brugada syndrome, short QT syndrome
78
name two inherited cardiomyopathies
hypertrophic cardiomyopathies, arrhythmogenic right ventricular cardiomyopathy (dilated right ventricle that causes arrhythmia), dilated cardiomyopathy
79
how do inherited cardiac conditions present
can have no symptoms, heart rhythm, palpitations, fast heart rate, fainting, breathlessness, chest pain, swollen legs, weakness, sudden death
80
how are inherited cardiac conditions diagnosed
clinical testing, genetic tests
81
how are the risks of inherited cardiac conditions managed
risk management, lifestyle, pharmacological and non pharmacological intervention
82
what electrical activity is mainly affected in a channelopathies
depolarisation
83
when should inherited cardiac conditions be considered in patients
young people with AF
84
what channel is mostly affected in long QT syndrome
potassium channel
85
what does congenital long QT syndrome look like on an ECG
polymorphic VT (torsades de pointes)
86
what triggers the polymorphic VT seen in LQTS
adrenergic stimulation
87
is LQTS autosomal dominant or recessive
can be both- 13 subtypes
88
what is the mechanism behind LQTS
less repolarising current and more depolarising current prolongs AP depolarisation
89
what can trigger LQTS
exercise, emotional stress, sleep, sudden auditory stimuli, QT prolonging conditions (medications, hypokalaemia)
90
what is the primary presenting complaint of LQTS
syncope, sudden cardiac death
91
how is congenital LQTS managed
avoidance of stimuli (swimming, breath holding, loud sudden noises), correction of electrolyte adnormalities, avoidance of QT prolonging drugs
92
what creates risk of SCD in LQTS
age dependent, gender (pre-teen boys, adult females), increasing QT duration, prior syncope
93
what can be shown on an ECG in brugada syndrome
risk of polymorphic VT, VF, AF common, ST elevation, RBBB in V1-3
94
how does brugadas commonly present
in young men who go to sleep and dont wake up
95
what types of inheritance pattern does brugadas have
autosomal dominant
96
what can trigger VF in brugada
rest or sleep, fever, excessive alcohol, large meals
97
what drugs should be avoided in brugada
anti-arrhythmic, psycotropics (used in schizophrenia), analgesics, anaesthetics
98
what is catecholaminergic polymorphic ventricular tachycardia
channelopathy
99
describe CPVT
Adrenergic induced bidirectional and polymorphic VT, SVTs, triggered by emotional stress, physical activity
normal ECG and echo
both autosomal dominant and recessive
100
how is risk managed in CPVT
avoidance of strenuous activity, stressful environments
beta blockers and ICD implantation (sometimes flecainide)
101
what are the clinical presentations of hypertrophic cardiomyopathies
sudden death, heart failure, angina, atrial fibrillation, asymptomatic
102
how is heart failure in HOCM treated
beta blockers, ACE I, diuretics, consider transplantation
103
how is AF or atrial flutter treated
oral anticoagulant, antithrombotic, amiodarone to restore sinus rhythm and b blockers, verapamil and diliazem to maintain / catheter ablation
104
what is lamin A/C
gene where mutations associated with DCM
105
What is SAD
syncope angina dyspnoea
106
what are after depolarisations
abnormal depolarisations if cardiac myocytes that interrupt phase 2, 3 or 4 of the cardiac AP in the cardiac conduction system of the heart
can lead to triggered activity
107
what are early depolarisations
) occur with abnormal depolarization during phase 2 or phase 3, and are caused by an increase in the frequency of abortive action potentials before normal repolarization is completed
can result in Torsades de Pointes
108
what is a treatment for DCM
ICD- implantable cardiac defibrillator
109
what causes arrhythmogenic right ventricular cardiomyopathy
fibro-fatty replacement of cardiomyocytes
110
what adds to the risk of SCD
```
Family history of premature SCD
Severity of RV and LV function
Frequent non-sustained VT
ECG : QRS prolongation
VT induction on EPS
Male gender
Age of presentation
```
111
what can help prevent SCD in pre symptomatic patients
life style changes, beta blockers, ICDs
112
describe embryonic folding
when embryo folds laterally and longitudinally, making the two initial heart tubes fuse, moving them into the midline, and making them start to beat
happens at 18 days
113
what happens when the two primitive heart tubes fuse together
form single primordial heart tube situated in the midline of the embryo
114
what is the trunctus arteriosus and what does it form
cranial segment of embryonic heart which forms pulmonary and aortic trunks
115
what is heart tube looping
when tubular heart forms a c then an s shape which resembles adult heart
116
describe sepation of the heart
the formation of atria and ventricles in the embryonic heart from endocardial cushions
117
what is the role of cardinal veins
return poorly oxygenated blood from the body if the embryo
118
what is the role of the foramen ovale
allows blood to travel from the right to the left atrium (shunt)
119
what is the role of the ductus venosus
allows blood from the umbilical vein to bypass the liver into the IVC
120
what is the role of the ductus arteriosus
allows blood to pass from the pulmonary trunk into the aorta (blood can bypass the lungs, liver and kidneys whose functions are performed by the placenta)
121
what germ layer is the heart formed from
mesoderm
