Congenital CV Disease Flashcards
(89 cards)
1
Q
Define congenital heart defects.
A
Congenital heart defects are problems with the heart’s structure that are present at birth.
2
Q
What structures of the heart can be affected by congenital heart defects ?
A
- The interior walls of the heart
- The valves inside the heart
- The arteries and veins that carry blood to the heart or the body
3
Q
How severe are congenital heart defects ? How tough of treatment do they require ?
A
They range from simple defects with no symptoms to complex defects with severe, life- threatening symptoms.
Many of these defects are simple conditions that need no treatment or are easily fixed but some babies are born with complex congenital heart defects that require special medical / surgical care soon after birth (but many of the latter survive to adulthood and can live active, productive lives)
4
Q
Do congenital heart defects affect blood flow through the heart ?
A
Yes, congenital heart defects change the normal flow of blood through the heart.
5
Q
How many babies out of 1000 are affected by congenital heart disease ?
A
8 in 1000
6
Q
What is the most common type of congenital defect ? What is the congenital defect that causes the most deaths within the first year of life ?
A
Congenital Heart Defects (CHD) are the most common type of birth defect. Also, complex CHD causes more deaths in the first year of life than any other birth defects.
7
Q
What are the possible categories of Congenital Heart Defects ?
A
Non-cyanotic and Cyanotic
8
Q
What is cyanosis ?
A
Blue skin colour caused by a lack of oxygen
9
Q
Identify cyanotic congenital heart defects.
A
Tetralogy of Fallot Total anomalous pulmonary venous return Transposition of the great vessels Tricuspid atresia Truncus arteriosus (^5 Ts)
Hypoplastic left heart
Pulmonary atresia
Ebstein’s anomaly (severe)
10
Q
Identify non cyanotic congenital heart defects.
A
- Ventricular septal defect (VSD)
- Atrial septal defect (ASD)
- Patent ductus arteriosus (PDA)
- Coarctation of the aorta
- Pulmonary stenosis
- Aortic stenosis
- Atrioventricular canal (endocardial cushion defect)
- Ebstein’s anomaly (mild)
11
Q
How can you further divide cyanotic, and non-cyanotic CHDs into categories ?
A
With shunt and without shunt (with shunt means there is pattern of blood flow in the heart that deviates from the normal circuit of the circulatory system).
Can also divide them into sub-categories depending on what’s wrong:
1) Cyanotic: Increased pulmonary flow, or obstruction to blood flow the aorta
2) Non-Cyanotic: Decreased pulmonary flow, or mixed blood flow
12
Q
Rank the most common congenital heart diseases.
A
- Ventricular Septal Defect 39%
- Atrial Septal Defect 10%
- Patent Ductus Arteriosus 10%
- Coarctation of the aorta 7%
- Pulmonary Stenosis 7%
- Aortic Stenosis 6%
- Fallot’s Tetralogy 6%
- Others 15%
13
Q
What other types of congenital issues may CHDs be present with ?
A
Most children with CHD do not have other types of birth defects. However, heart defects may be part of genetic and chromosomal syndromes. E.g. • Down syndrome (Trisomy 21) • DiGeorge syndrome • Edward syndrome (Trisomy 18) • Marfan syndrome • Noonan syndrome • Patau syndrome (Trisomy 13) • Turner syndrome
14
Q
What proportion of all infants affected by significant CHD are also found to have extra-cardiac anomalies (ECAs) during the first year of life ?
A
25%
15
Q
What are ECAs ?
A
Extracardiac anomalies, abnormalities outside of the heart which may be found alongside congenital heart disease.
16
Q
Where are ECAs found ?
A
The most frequent ECA are in the musculoskeletal system or associated with a specific syndrome (one third of the affected infants have some established syndrome)
17
Q
What is the significance of ECA ?
A
The presence of an ECA significantly increases the mortality in infants with CHD.
18
Q
Are ECAs usually present in single or multiple quantities ?
A
Often the ECA are multiple
19
Q
What are the main causes of congenital heart diseases ?
A
- Drugs such as retinoic acid for acne, chemicals, alcohol, and infections (such as rubella) during pregnancy can contribute to some congenital heart problems.
- Poorly controlled blood sugar in women who have diabetes during pregnancy has also been linked to a high rate of congenital heart defects.
- Often, no cause for the heart disease can be found.
20
Q
What are the symptoms of Congenital Heart Defects ?
A
• Symptoms depend on the condition.
21
Q
What is the timeline of the appearance of symptoms in congenital heart disease ?
A
- Depends on the condition
- Although congenital heart disease is present at birth, the symptoms may not appear right away.
- Defects such as coarctation of the aorta may not cause problems for years.
- Other problems, such as a small VSD, ASD, or PDA may never cause any problems.
22
Q
Describe the symptoms / signs of heart failure in infants with CHD.
A
- Cyanosis (> 5g/dl deoxyhaemoglobin)
- Rapid breathing (Tachypnoea)
- Extra work of breathing
- Grunting
- Tachycardia
- Poor blood circulation
- Fatigue (Poor feeding)
- Faltering growth
- Sweating
- Enlarged Liver (Hepatomegaly)
- Murmurs
23
Q
Identify possible complications of congenital heart disease.
A
- Faltering growth (previously referred to as “failure to thrive”)
- Paradoxical embolus (embolus from venous to arterial)
- Bacterial endocarditis
- Pulmonary hypertension
- Polycythaemia (high RBCs)
- Haemoptysis (coughing blood)
- Arrhythmias
24
Q
Describe the main features of ventricular septal defects (VSD).
- Definition
- Incidence (as a proportion of all CHDs)
- Does it require treatment
- Consequences of it on the heart/circulation
A
- Incidence: 39% of all cases of congenital heart disease
- Definition: “a hole in the wall of the heart (septum) that separates LV from RV. This allows blood to flow from the left ventricle to the right ventricle instead of entering the aorta for distribution”
- Do they require treatment ? VSDs can be small, medium, or large. Small VSDs don’t cause problems and may close on their own. Medium VSDs are less likely to close on their own and may require treatment.
- Consequences of larger VSD: Large VSDs allow a lot of blood to flow from the left ventricle to the right ventricle. As a result, the left side of the heart must work harder than normal. Extra blood flow increases blood pressure in the right side of the heart and the lungs. The heart’s extra workload can cause heart failure and poor growth. If the hole isn’t closed, high blood pressure can scar the arteries in the lungs leading to the dreaded complication of Pulmonary Hypertension and irreversible damage leading to shunt reversal and Eisenmenger’s Syndrome.
25
How may VSDs be closed ?
- Surgically
| - Interventional radiology, through trans-arterial devices (less invasive)
26
Describe the main features of atrial septal defects (ASD).
- Definition
- Incidence (as a proportion of all CHDs)
- Does it require treatment
- Consequences of it on the heart/circulation
- Incidence: 10%
- Definition: Hole in the wall separation RA and LA
- Do they require treatment ? ASDs can be small, medium, or large. Small ASDs allow only a little blood to leak from one atrium to the other. They don't affect how the heart works and don't need any special treatment. Many small ASDs close on their own as the heart grows during childhood. About half of all ASDs close on their own over time. Medium and large ASDs allow more blood to leak from one atrium to the other. They’re less likely to close on their own.
- Consequences of ASD: If there is a longstanding significant left to right shunt through the ASD the increased blood flow through the lungs can scar the arteries in the lungs leading to the dreaded complication of Pulmonary Hypertension.
27
How may medium and large ASDs which require treatment be closed ?
Medium and large ASDs that need treatment can be repaired using a catheter procedure or open-heart surgery.
28
Describe the main features of Patent Ductus Arteriosus including
- Definition
- Incidence (as a proportion of all CHDs)
- Does it require treatment
- Consequences of it on the heart/circulation
- Incidence: 10%
- Definition: persistent communication between the descending thoracic aorta and the pulmonary artery that results from failure of normal physiological closure of the foetal ductus.
- Does it require treatment: If significant respiratory distress or impaired systemic oxygen delivery is present, therapy is usually prudent.
- Consequences: possibly, significant respiratory distress or impaired systemic oxygen delivery
29
How may Patent Ductus Arteriosus be treated ?
* Intravenous indomethacin or ibuprofen is frequently effective in closing a PDA if it is administered in the first 10-14 days of life.
* Other options are catheter closure and surgical ligation.
30
What is the ductus arteriosus ?
During foetal life, the ductus arteriosus is a normal structure that allows most of the blood leaving the right ventricle to bypass the pulmonary circulation and pass into the descending aorta.
31
In fetal circulation, how much of the right ventricular output passes through the pulmonary vascular bed ? Where else does it go ?
Typically, only about 10% of the right ventricular output passes through the pulmonary vascular bed. Through Foramen Ovale, Ductus Arteriosus.
32
Explain the transition from fetal to neonatal circulation.
FETAL CIRCULATION
1. Blood enters the right atrium, the chamber on the upper right side of the heart. When the blood enters the right atrium, most of it flows through the foramen ovale into the left atrium.
2. Blood then passes into the left ventricle (lower chamber of the heart) and then to the aorta
3. From the aorta, blood is sent to the heart muscle itself in addition to the brain. After circulating there, the blood returns to the right atrium of the heart through the superior vena cava. About two thirds of the blood will pass through the foramen ovale as described above, but the remaining one third will pass into the right ventricle, toward the lungs.
4. In the fetus, the placenta does the work of breathing instead of the lungs. As a result, only a small amount of the blood continues on to the lungs. Most of this blood is bypassed or shunted away from the lungs through the ductus arteriosus to the aorta. Most of the circulation to the lower body is supplied by blood passing through the ductus arteriosus.
5. This blood then enters the umbilical arteries and flows into the placenta. In the placenta, carbon dioxide and waste products are released into the mother's circulatory system, and oxygen and nutrients from the mother's blood are released into the fetus' blood.
NEONATAL CIRCULATION
At birth, the umbilical cord is clamped and the baby no longer receives oxygen and nutrients from the mother. With the first breaths of life, the lungs begin to expand. As the lungs expand, the alveoli in the lungs are cleared of fluid. An increase in the baby's blood pressure and a significant reduction in the pulmonary pressures reduces the need for the ductus arteriosus to shunt blood. These changes promote the closure of the shunt. These changes increase the pressure in the left atrium of the heart, which decrease the pressure in the right atrium. The shift in pressure stimulates the foramen ovale to close.
The closure of the ductus arteriosus and foramen ovale completes the transition of fetal circulation to newborn circulation.
33
Define Patent F. Ovale.
Flaplike opening between the atrial septa primum and secundum at the location of the fossa ovalis that persists after age 1 year.
34
How does the foramen ovale normally close ?
* Immediately after birth, pressure in the right side of the heart and pulmonary vascular resistance diminish abruptly as the pulmonary alveoli fill.
* This, together with greater pressure in the left atrium due to increased venous return, produces functional closure of the foramen ovale which in 75% of people closes structurally in infancy.
35
What is the incidence of PFO in the population ?
Approx 25% of people have a PFO.
36
Is PFO a CHD ?
No, it is considered a normal condition rather than a form of Congenital Heart Disease.
37
Why is a PFO not considered an ASD ?
Because no septal tissue is missing and there is no significant shunting.
38
Can PFOs have pathological consequences ?
Rarely PFO can be the culprit in paradoxical embolic events.
39
What other defects does aortic coarctations often occur with ?
CoA may occur as an isolated defect or in association with various other lesions, most commonly bicuspid aortic valve and VSD.
40
How is aortic coarctation diagnosed ?
The diagnosis of CoA may be missed unless an index of suspicion is maintained, and diagnosis is often delayed until the patient develops congestive heart failure, which is common in infants, or hypertension, which is common in older children.
41
Define aortic coarctation.
Constricted aortic segment
42
Where do aortic coarctations usually occur ?
The classic CoA is located in the thoracic aorta distal to the origin of the left subclavian artery at about the level of the ductal structure.
43
What are the possible consequences of aortic coarctation on the heart and circulation ?
- CoA imposes significant afterload on the left ventricle, which results in increased wall stress and compensatory ventricular hypertrophy.
- The afterload may be imposed acutely, as occurs following closure of the ductus arteriosus in neonates with severe coarctation. These infants may rapidly develop congestive heart failure and shock.
44
Describe the clinical presentation of aortic coarctation.
* Varies accordingly to the degree of stenosis and the associated abnormalities.
* Patients may be asymptomatic in a setting of a non-severe stenosis.
* Children and adults can present with angina pectoris and leg claudication.
* On clinical examination, diminished femoral pulses and differential blood pressure between upper and lower extremities may be noted.
45
What is the prognosis and timeline for treatment, for aortic coarctation ?
- Depends on the presence of congestive heart failure (usually the case in severe coarctations found in infancy)
- In less severe cases, elective treatment when the child is older (typically ~2 years of age) is preferred .
46
Describe the treatment for aortic coarctation.
1) Subclavian flap repair, surgical technique where the origin and proximal left subclavian artery is excised, opened up and sutured onto the aorta. If the subclavian is ligated, it is usually anastomosed onto the left common carotid artery.
OR
2) Balloon angioplasty
47
What kinds of congenital heart disease affects valves inside the heart ? Define each.
- Atresia: if a valve doesn't form correctly and lacks a hole for blood to pass through. Atresia of a valve generally results in more complex congenital heart disease
- Stenosis: if the flaps of a valve thicken, stiffen, or fuse together. As a result, the valve cannot fully open. Thus, the heart has to work harder to pump blood through the valve
- Regurgitation: if a valve doesn't close tightly. As a result, blood leaks back through the valve
48
What is the most common valve defect ?
Pulmonary valve stenosis
49
Describe the main features of pulmonary valve stenosis.
- Incidence (as a proportion of all CHDs)
- Does it require treatment ?
- Consequences on heart and circulation
- Incidence: 7%
- Does it require treatment ? Pulmonary valve stenosis can range from mild to severe. Most children who have this defect have no signs or symptoms other than a heart murmur. Treatment isn't needed if the stenosis is mild. If severe, treatment is needed.
- Consequences on heart and circulation: in babies who have severe pulmonary valve stenosis, the right ventricle can get very overworked trying to pump blood to the pulmonary artery. These infants may have signs and symptoms of heart failur
50
What is the treatment for severe pulmonary valve stenosis ?
Catheter Procedure (Balloon Valvuloplasty)
51
What are the consequences of aortic valve stenosis on the heart and circulation ?
It causes mild to severe obstruction of the left ventricular outflow that may be associated with other left heart obstructive lesions, varying degrees of left heart hypoplasia, or extracardiac malformations, including genetic disorders.
52
When (in their lifetime) do patients usually present with aortic valve stenosis ?
* An estimated 10-15% of patients with aortic valve stenosis present with the condition when they are younger than 1 year due to severe stenosis.
* The remainder of patients may present later in childhood or in adulthood due to progressive obstruction.
* Adult patients with bicuspid aortic valves may develop significant stenosis or insufficiency after the valve becomes calcified in the fourth, fifth, or sixth decade of life.
53
What is the treatment for aortic valve stenosis ?
* Balloon aortic valvuloplasty is the initial treatment of choice in pediatric patients with congenital aortic valve stenosis
* Surgical repair or replacement of an aortic valve is primarily reserved for patients in whom balloon valvuloplasty has failed with severe stenosis or have significant valve insufficiency in association with progressive left ventricular dilation or deterioration of left ventricular systolic function
54
What is the most common COMPLEX heart defect ?
Tetralogy of Fallot
55
Describe the main features of the Tetralogy of Fallot.
- Incidence (as a proportion of all CHDs)
- Definition
- Clinical observations
-Incidence: 6%
-Definition: A combination of four defects:
• Pulmonary valve stenosis
• A large VSD
• An overriding aorta
• Right ventricular hypertrophy
-Clinical observations: Tet spells (not always)
56
What is meant by overriding aorta, in the Tetralogy of Fallot ?
The aorta is located between the left and right ventricles, directly over the VSD. As a result, oxygen-poor blood from the right ventricle can flow directly into the aorta instead of into the pulmonary artery.
57
How many newborns have the Tetralogy of Fallot ?
1 in 2000
58
Does sex influence risk of being affected by the Tetralogy of Fallot ?
No, males and females are affected equally.
59
What are the Tet spells, witnessed in the Tetralogy of Fallot ?
- Sudden episodes of profound cyanosis and hypoxia (tet spell) may occur
- Can be lethal
- A spell may be triggered by any event that slightly decreases oxygen saturation (eg, crying, defecating) or that suddenly decreases systemic vascular resistance (eg, playing, kicking legs when awakening) or by sudden onset of tachycardia or hypovolemia
- Mechanism remains uncertain, but several factors are probably important in causing an increase in right-to- left shunting and a fall in arterial saturation
60
What is the treatment of TOF ?
Must be repaired with open-heart surgery, either soon after birth or later in infancy.
- Palliative Surgery (Blalock-Taussig shunt): forming a side to end anastomosis between the subclavian artery and the pulmonary artery, redirecting a large portion of the partially oxygenated blood leaving the heart for the body into the lungs, increasing flow through the pulmonary circuit, and greatly relieving symptoms in patients.
- Now, total repair (curative) surgery
61
What does the timing of the surgery for TOF depend on ?
The timing of the surgery will depend on how narrow the pulmonary artery is.
62
Are there any risks associated with the curative surgery for TOF ?
- 90% survival rate, and large majority of patients who undergo corrective surgery within the first two years of life lead normal lives without significant cardiac or vascular symptoms.
- However, some patients experience increased rates of mortality and morbidity in adulthood
63
Identify the risk factors for late sudden cardiac death in adults following surgical repair of Tetralogy of Fallot.
- RV hypertrophy, ventricular dysfunction and atrial tachyarrhythmias
- Also the quality of surgical correction (residual outflow obstruction and pulmonary regurgitation of particular importance)
64
Describe the incidence and demographics of Hypoplastic Left Heart Syndrome (HLHS).
* Hypoplastic left heart syndrome occurs in up to four out of every 10,000 live births.
* 8% of all of all cases of congenital heart disease
* HLHS occurs slightly more often in boys than in girls.
65
Define HLHS.
"Congenital hypoplasia or atresia of the left ventricle, the aortic or mitral valve, and the ascending aorta, with respiratory distress, cardiac failure, and death in infancy"
66
Describe the onset of symptoms of HLHS.
* Babies with hypoplastic left heart syndrome may seem normal at birth because the patent ductus arteriosus is still open, allowing blood to continue circulating directly into the aorta and out to the rest of the body.
* Once the ductus closes a few days after birth, blood flows to the lungs and then to the left side of the heart where it is blocked and can’t circulate through the rest of the body. It is at this time that these babies show symptoms.
67
How is HLHS treated ?
Initial treatment:
• Newborns are commenced on an IV infusion of prostaglandin E1 to keep the ductus arteriosus open immediately after birth (lets oxygenated blood reach the body)
• The child may need a balloon septostomy soon after birth, if the foramen ovale is too small and there is not sufficient blood flow.
ALSO
* HLHS is treated with surgery. This can involve either a series of 3 heart surgeries or, less commonly, heart transplantation.
* In some instances, a hybrid procedure involving a combination of surgery and cardiac catheterization may be used to treat the child in place of the first in a series of 3 surgeries.
68
Explain the procedure of Balloon Atrial Septostomy in the initial treatment of HLHS.
- Catheter with a balloon on the end. It is guided through a blood vessel into the heart. The balloon is inflated to widen the foramen ovale.
- Sometimes, a stent may be placed to keep the hole open. This allows more blood to mix freely between the atria
69
Define transposition of the great vessels.
The pulmonary arteries are supplied by the left ventricle, and the aorta by the right ventricle.
70
What does survival of infants with transpositon of the great vessels depend on ?
Infants can only survive if there is a shunt between the two sides of the heart, and an atrial septal defect needs to be actually enlarged to allow adequate mixing of blood to deliver enough oxygenated blood to the body
71
What is the treatment for transposition of the great vessels ?
Balloon Septostomy, to expand ASD
| Surgical treatment
72
Define Truncus Arteriosus.
Both aorta and pulmonary arteries arise from a common "trunk", causing blood from both ventricles to mix together as it all exits through the single valve exiting from the heart.
73
Describe the treatment for Truncus Arteriosus.
Sewing a flexible tube with its own valve from the right ventricle to bring blood to the pulmonary arteries.
74
Define Ebstein’s Anomaly. How severe is it ?
-Malformation of the tricuspid valve, so while there is free flow of blood forward across the tricuspid valve to the right ventricle, the deformed tricuspid valve allows a large amount of blood to flow backwards from the right ventricle to right atrium when the right ventricle contracts.
At the milder end of the spectrum it will be acyanotic (people may have a normal life expectancy). If the tricuspid valve is severely incompetent then the right atrial pressure will be significantly increased.
If there is an associated ASD then you will get a right to left shunt at atrial level giving some degree of cyanosis. Depending on severity and the size of the ASD this may be present at birth or may develop later in life. It can also happen in the presence of a patent foramen ovale.
75
Describe the treatment for Ebstein's anomaly.
The treatment of this disorder depends on whether or not the person with it has any symptoms.
Surgery is sometimes required early in life.
76
Define Total Anomalous Pulmonary Venous Drainage.
• The Pulmonary Veins, which carry blood back to the heart after it has circulated through the lungs, are not connected to the left atrium. Instead, they are connected to one of the veins from the main circulation so that the blood returning from the lungs drains back to the right side of the heart.
77
Describe the treatment for Total Anomalous Pulmonary Venous Drainage.
Most of the time, surgical repair in the newborn period.
78
What clinical signs/symptoms are present in Total Anomalous Pulmonary Venous Drainage.
The affected babies may be blue or show signs of heart failure.
79
Define Atrioventricular Septal Defect (AVSD). Describe any demographic specificity of this defect.
= AV canal defect or endocardial cushion defect
Heart defect in which there are holes between the chambers of the right and left sides of the heart, and the valves that control the flow of blood between these chambers may not be formed correctly.
-AVSD is common in babies with Down syndrome
80
What factors made women more likely to report that they had received a diagnosis of CHD during pregnancy ?
* They were over 30 years of age
* They had type 1 or 2 diabetes
* Someone else in their family had a CHD
* They were carrying twins or multiple babies
* Their baby had a more complex heart defect or other birth defects in addition to the CHD
81
Identify a way to diagnose CHD from a neonate.
Post ductal pulse oximetry in detection of critical duct dependent heart lesions (checks if the bottom half of the body is well oxygenated. If less than 95%, should check)
82
Identify causes of sudden unexpected collapse in first week of life.
* Duct dependent CHD.
* Sepsis (particularly Group B Strep).
* Hypoglycaemia.
* Congenital Adrenal Hyperplasia.
* Inborn errors of metabolism.
83
Define duct dependent CHD. Give examples.
Ductal-dependent lesions require the ductus arteriosus for adequate pulmonary circulation and include: Tetralogy of Fallot, tricuspid atresia or Ebstein’s anomaly, and pulmonic atresia or stenosis.
84
Define Eisenmenger’s Syndrome.
=“Acquired Cyanotic Heart Disease”
• Shunt reversal.
• Initially large left to right shunt such
as large VSD.
• Patient develops Pulmonary Arterial Hypertension to the point of right sided heart pressure exceeding left with shunt reversal (now right to left) and development of cyanosis.
85
Describe the treatment and prognosis for Eisenmenger’s Syndrome.
* Poor prognosis.
| * Treatment is generally supportive, but heart and lung transplantation may be an option when symptoms are severe.
86
Identify the acyanotic CHDs with shunts, and without.
With Shunts
ASD
VSD
PDA
Without Shunts
Pulmonary stenosis
Coarctation of aorta
Aortic/L heart obstruction
87
Identify the cyanotic CHDs with shunts, and without.
With Shunts
Transposition of the great vessels
TOF
Eisenmenger’s Syndrome
Without Shunts
Hypoplastic L heart
Very severe pulmonary stenosis
Pulmonary/Tricuspid atresia with or without intact septum
88
Identify the acyanotic CHDs associated with increased pulmonary flow, and those associated with obstruction to blood flow from ventricles.
```
Increased Pulmonary Blood Flow:
ASD
VSD
PDA
AV canal
```
Obstruction to blood flow from ventricles:
Coarctation of aorta
Aortic stenosis
Pulmonary stenosis
89
Identify the cyanotic CHDs associated with decreased pulmonary flow, and those associated with mixed blood flow.
Decreased Pulmonary Blood Flow:
TOF
Tricuspid atresia
```
Mixed Blood Flow:
Transposition of great vessels
Total anomalous pulmonary venous return
Truncus Arteriosus
Hypoplastic L heart syndrome
```
