CONGENITAL HEART DISEASE (AB) Flashcards
3 cardiovascular structures unique to the fetus
Ductus venosus, Foramen ovale (located at the interatrial septum), Ductus arteriosus (if it stays open, it is called patent ductus arteriosus)
What happens when there is a disruption in the flow of blood within the heart chambers?
Congenital heart defects may occur.
What happens in tricuspid valve atresia?
Restricted blood flow to the right ventricle, leading to underdevelopment of the right ventricle and pulmonary artery.
Examples of right-sided cardiac lesions
Tricuspid valve atresia, hypoplastic right ventricle, pulmonary atresia.
Where does exchange of metabolites and oxygen occur in the fetus?
Placenta
What are the components of the umbilical cord?
Two arteries and one vein (AVA).
Pathway of oxygenated blood entering the fetus
Umbilical vein → liver (some) → ductus venosus → inferior vena cava (IVC) → right atrium (RA)
Why is blood shunted from the right atrium to the left atrium via the foramen ovale?
Because the right side of the heart has higher pressure than the left side in utero.
What is the main ventricle in intrauterine circulation?
Right ventricle
What happens after birth when the lungs expand?
Pulmonary vascular resistance decreases, blood flows to the lungs, and oxygen exchange occurs.
What happens to the ductus arteriosus and ductus venosus after birth?
They constrict due to increased oxygen levels.
What causes the physiological closure of the foramen ovale?
Increased blood flow to the left atrium after birth.
By what age is anatomical closure of the foramen ovale expected?
2 months of age
What is the first step in evaluating congenital heart disease (CHD)?
Thorough history taking and physical examination
Prevalence of symptomatic congenital heart disease in newborns
2-3 per 1000 live births
Most common cyanotic congenital heart disease
Tetralogy of Fallot
Most common complex congenital heart disease
Transposition of the great arteries
Genetic conditions associated with CHD
DiGeorge Syndrome (22q11.2 deletion), CATCH 22, Conotruncal defects (TOF, TA, DORV, VSDsubarterial), Brachial arch defects (COA, IAA, Right Aortic Arch)
Environmental factors linked to CHD
Maternal diabetes, maternal PKU, SLE, congenital rubella syndrome, maternal use of lithium, ethanol, warfarin, vitamin A derivatives, and AEDs.
Common L→R shunt lesions
Ventricular septal defect (VSD), Atrial septal defect (ASD), Patent ductus arteriosus (PDA), Coarctation of aorta
Key clinical features of cyanotic congenital heart disease
Squatting, cyanosis, clubbing, syncope
What diagnostic tool helps assess pulmonary blood flow in CHD?
Chest X-ray
How does left ventricular hypertrophy (LVH) present on ECG?
Large R waves in left-sided leads (V5, V6, aVL, I) and deep S waves in right-sided leads (V1, V2).
How does right ventricular hypertrophy (RVH) present on ECG?
Large R waves in right-sided leads (V1-V3) and deep S waves in left-sided leads.
What is Eisenmenger syndrome?
Reversal of a left-to-right cardiac shunt due to increased pulmonary vascular resistance, leading to cyanosis.
What are the five basic questions for evaluating congenital heart disease?
- Cyanotic or Acyanotic? 2. Pulmonary blood flow: Normal, Increased, or Decreased? 3. Origin: Left or Right heart? 4. Dominant ventricle? 5. Pulmonary hypertension present?
How can pulmonary blood flow (PBF) help narrow the differential diagnosis of congenital heart disease?
“Assess whether PBF is increased. normal or decreased using imaging.”
What is the predominant finding in pulmonary stenosis if acyanotic congenital heart disease has normal or decreased PBF?
“Right ventricular hypertrophy (RVH).”
What is the predominant finding in aortic stenosis if acyanotic congenital heart disease has normal or decreased PBF?
“Left ventricular hypertrophy (LVH).”
What are common history findings in a patient with pulmonary stenosis?
“Fatigue. exertional dyspnea. syncope (in severe cases). right-sided heart failure symptoms (peripheral edema. hepatomegaly).”
What type of murmur is associated with pulmonary stenosis, and where is it best heard?
“Systolic ejection murmur best heard at the left upper sternal border (LUSB).”
What additional physical exam findings may be present in pulmonary stenosis?
“Wide splitting of S2. ejection click that decreases with inspiration. jugular venous distention (JVD) in severe cases. right ventricular heave.”
What type of murmur is heard in aortic stenosis?
“Systolic ejection murmur (crescendo-decrescendo).”
Where is the murmur of aortic stenosis best heard?
“Right second intercostal space (aortic area).”
Where does the murmur of aortic stenosis radiate?
“To the carotids.”
What type of murmur is heard in aortic regurgitation?
“Diastolic decrescendo murmur.”
Where is the murmur of aortic regurgitation best heard?
“Left third intercostal space (Erb’s point).”
Where does the murmur of aortic regurgitation radiate?
“To the apex.”
What type of murmur is heard in mitral stenosis?
“Diastolic low-pitched rumbling murmur with an opening snap.”
Where is the murmur of mitral stenosis best heard?
“Apex (left 5th ICS. midclavicular line).”
What type of murmur is heard in mitral regurgitation?
“Holosystolic (pansystolic) murmur.”
Where is the murmur of mitral regurgitation best heard?
“Apex.”
Where does the murmur of mitral regurgitation radiate?
“To the axilla.”
What are the four auscultation sites for heart sounds?
“1. Right Upper Sternal Border (RUSB) - Aortic area 2. Left Upper Sternal Border (LUSB) - Pulmonic area 3. Left Lower Sternal Border (LLSB) - Tricuspid area 4. Apex - Mitral area.”
What condition is suspected if a murmur at the LUSB persists beyond 7 days in a newborn?
“Pulmonary stenosis.”
What congenital heart diseases are associated with increased pulmonary blood flow and right ventricular hypertrophy (RVH)?
“Atrial septal defect (ASD)
What are the primary considerations for cyanotic congenital heart disease with decreased pulmonary blood flow and RVH?
“Tetralogy of Fallot (TOF). Ebstein’s anomaly.”
What are the primary considerations for cyanotic congenital heart disease with decreased pulmonary blood flow and LVH?
“Tricuspid atresia. Pulmonary atresia with hypoplastic right ventricle.”
What are the primary considerations for cyanotic congenital heart disease with decreased pulmonary blood flow and combined ventricular hypertrophy (CVH)?
“Truncus arteriosus. single ventricle morphology.”
What are the primary considerations for cyanotic congenital heart disease with increased pulmonary blood flow and RVH?
“Transposition of the Great Arteries (TGA) with Intact Ventricular Septum (IVS). Total Anomalous Pulmonary Venous Connection (TAPVC). Hypoplastic Left Heart Syndrome (HLHS).”
What are the primary considerations for cyanotic congenital heart disease with increased pulmonary blood flow and CVH/LVH?
“TGA with Ventricular Septal Defect (VSD). Single ventricle morphology.Truncus arteriosus. Pulmonary Veno-Occlusive Disease (PVOD).”
What does ‘unobstructed & unprotected’ pulmonary circulation in cyanotic congenital heart disease lead to?
“Pulmonary vasculature is exposed to high pressures and volume overload. causing pulmonary hypertension.”
What is Eisenmenger syndrome?
“A condition where an untreated left-to-right shunt reverses due to pulmonary hypertension. causing cyanosis and systemic hypoxemia.”
What congenital heart diseases are associated with left-to-right shunt lesions?
“Atrial septal defect (ASD). Ventricular septal defect (VSD). Atrioventricular septal defect (AVSD). Patent ductus arteriosus (PDA).”
What is the significance of Qp:Qs in congenital heart disease?
“Quantifies pulmonary (Qp) to systemic (Qs) blood flow; normal is 1:1. large left-to-right shunts have Qp:Qs >2:1. right-to-left shunts cause cyanosis.”
What are signs of Eisenmenger physiology?
“Gradual increase in pulmonary vascular resistance. initial improvement of heart failure symptoms. followed by progressive cyanosis.”
How is management of left-to-right shunts determined?
“Small defects may close spontaneously; large defects require medications (digoxin. diuretics. ACE inhibitors) and surgery if symptomatic.”
What is the most common congenital heart defect (CHD), accounting for 25% of cases?
Ventricular Septal Defect (VSD)
Where can a VSD occur?
Anywhere along the interventricular septum (IVS)
What are the two major determinants of left-to-right (L-R) shunting in VSD?
Defect size and pulmonary vascular resistance (PVR)
What is the perimembranous type of VSD associated with?
Shunting seen around the 10 o’clock position; at 12 o’clock, it is the subarterial type
What is a characteristic feature of small perimembranous VSD?
Chance of spontaneous closure
Which type of VSD has shunting near the pulmonary artery?
Subpulmonic (Supracristal) VSD
What complication may arise in subpulmonic VSD?
Aortic valve destruction leading to aortic insufficiency
What is the recommended management for subpulmonic VSD?
Closure regardless of size due to risk of aortic valve involvement
What type of VSD has a high chance of spontaneous closure within the first 2 years of life?
Muscular VSD
Where is the murmur of VSD best heard?
Left midsternal border (between the left upper and left lower sternal borders)
What are the characteristics of a restrictive VSD?
Small defects (<5 mm)
What defines a non-restrictive VSD?
Defect >10 mm or >1 cm in size
What is the first-line diagnostic approach for VSD?
CXR and 15-lead ECG
What imaging modality is used to confirm VSD diagnosis?
2D echocardiogram with color flow Doppler studies
When is cardiac catheterization indicated for VSD?
When anatomy is unclear or operability needs to be assessed (e.g., suspected Eisenmenger Syndrome)
What percentage of small VSDs close spontaneously within the first 2 years of life?
30-50%
What type of VSD has an 80% chance of spontaneous closure?
Small muscular VSD
What is the AHA recommendation for elective closure of VSD?
All VSDs must be closed electively by mid-childhood
What condition may develop if a large VSD is left untreated?
Acquired infundibular pulmonary stenosis mimicking Tetralogy of Fallot (TOF)
What is the primary goal in managing infants with large VSDs?
Control heart failure symptoms and prevent pulmonary artery hypertension/Eisenmenger Syndrome
What is a sign that a medium-to-large VSD patient may be developing Eisenmenger Syndrome?
Apparent clinical improvement in symptoms with age
What is a major contraindication to VSD surgery?
Severe pulmonary vascular disease (PVD) and pulmonary artery hypertension non-responsive to vasodilators
What are two rare complications of surgical VSD repair?
Residual ventricular shunts and heart block requiring pacemaker placement
What is the purpose of pulmonary artery (PA) banding in VSD?
To protect the pulmonary bed from volume overload while awaiting definitive surgery
What is an Atrial Septal Defect (ASD)?
A defect across the interatrial septum due to failure of normal embryonic septal development
What are the three main types of ASD?
Secundum, Primum, and Sinus Venosus
Which ASD type is most commonly managed with interventional closure?
Secundum ASD
What syndrome is associated with secundum ASD and first-degree AV block?
Holt-Oram Syndrome
What is an incompetent Patent Foramen Ovale (PFO)?
A PFO that remains open but does not have hemodynamic significance
What is the physiological effect of ASD?
Volume overload in the right atrium (RA) and right ventricle (RV) due to left-to-right (L-R) shunting
What factors determine the degree of L-R shunting in ASD?
Defect size, RV/LV compliance, pulmonary and systemic vascular resistance
What is the characteristic murmur of ASD?
Systolic ejection murmur at the left upper sternal border (LUSB)
What is a hallmark auscultatory finding in ASD?
Wide and fixed splitting of the second heart sound (S2)
What diagnostic finding on CXR suggests ASD?
Obliteration of the retrosternal space indicating right ventricular hypertrophy (RVH)
What is the preferred treatment for ASD in early childhood?
Surgical or transcatheter closure
What is the treatment of choice for secundum ASD closure?
Percutaneous device closure using an atrial septal occlusion device
What is a major complication of ASD device closure?
Device erosion (risk minimized by selecting good candidates)
At what Qp/Qs ratio is ASD closure indicated?
≥ 2:1
What type of shunt is Patent Ductus Arteriosus (PDA)?
Left-to-right (L-R) shunt
What is the classic murmur of PDA?
Continuous ‘machinery-like’ murmur best heard at the left upper sternal border (LUSB) or second intercostal space, left parasternal border
What part of the cardiac cycle does the PDA murmur cover?
Both systole and diastole
What is the female-to-male ratio in PDA incidence?
2:1, more common in females
What congenital infection is associated with PDA?
Maternal/Congenital Rubella Syndrome
What percentage of congenital heart disease (CHD) cases does PDA account for?
6%-8%
What is the expected outcome of PDA in premature infants?
Spontaneous closure is common due to normal vessel anatomy of the ductus
What prevents spontaneous closure of PDA in term neonates?
Deficiency in mucoid endothelial layer and muscular media, preventing normal constriction
Why is it important to determine if a PDA patient is premature or term?
To predict the likelihood of spontaneous closure and provide appropriate counseling
When should PDA closure be maintained instead of treated?
In critical conditions such as severe pulmonary or right ventricular outflow obstruction (RVOT) where the PDA is the only source of pulmonary circulation
What are duct-dependent congenital heart diseases?
Conditions where systemic or pulmonary circulation depends on PDA patency, such as coarctation of the aorta (COA) or severe pulmonic valve stenosis/atresia
In what percentage of CHD cases does PDA serve as a source of pulmonary blood flow?
0.1
What clinical manifestations suggest a medium to large PDA?
Peripheral bounding pulses, widened pulse pressure, thrill maximal at LUSB
What happens to the PDA murmur if pulmonary vascular disease (PVD) develops?
Diastolic component may be absent, leaving only a systolic murmur
What is the characteristic murmur of PDA?
Continuous ‘machinery-like’ murmur best heard at the left upper sternal border (LUSB)
What are the classic chest X-ray findings in PDA?
Cardiomegaly, left atrial enlargement, increased pulmonary vascular markings, main pulmonary artery bulging
What are common differential diagnoses for a continuous machinery-like murmur?
Aortic-pulmonary window, ruptured sinus of Valsalva aneurysm, coronary arteriovenous fistula, truncus arteriosus with torrential pulmonary flow
Why is spontaneous PDA closure rare in term infants?
Persistent PDA beyond the first week of life is uncommon due to anatomical differences in the ductus
What are three major complications of an untreated large PDA?
Infective endarteritis, pulmonary/systemic emboli, Eisenmenger syndrome
What is the preferred treatment for PDA, regardless of age?
Catheter-based or surgical closure
When should a medium-to-large PDA be closed?
Closure should not be delayed once diagnosed to prevent complications
What is the standard treatment approach for PDA closure?
Transcatheter PDA closure
What device is used for small PDA closure?
Intravascular coils or small gap/device closure
How is a transcatheter PDA closure performed?
Approach via femoral artery to the descending aorta, reaching the ductus area for closure
What type of device is used for medium-to-large PDA closure?
Umbrella-like device
What is the embryologic abnormality in Atrioventricular Septal Defect (AVSD)?
Deficiency of the atrioventricular (AV) septum
Which genetic condition is AVSD most commonly associated with?
Down syndrome
What are the three key structural defects in AVSD?
Inlet VSD, ostium primum defect, cleft anterior mitral valve leaflet (AMVL)
What is a Gerbode shunt?
A left ventricle-to-right atrium (LV→RA) shunt due to absence of the AV septum
What is the pathophysiology of AVSD?
Left-to-right shunting at both atrial and ventricular levels
Why do AVSD patients have an early tendency to develop pulmonary vascular disease (PVD)?
High pulmonary blood flow leads to pulmonary hypertension
When is surgical correction of AVSD ideally performed?
Within 3-6 months of life, or before 1 year to prevent Eisenmenger syndrome
Why is early surgery especially crucial for AVSD patients with Down syndrome?
They have a higher tendency to develop Eisenmenger syndrome compared to non-chromosomal cases
What type of shunt is Patent Ductus Arteriosus (PDA)?
Left-to-right (L-R) shunt
What is the classic murmur of PDA?
Continuous ‘machinery-like’ murmur best heard at the left upper sternal border (LUSB) or second intercostal space, left parasternal border
What part of the cardiac cycle does the PDA murmur cover?
Both systole and diastole
What is the female-to-male ratio in PDA incidence?
2:1, more common in females
What congenital infection is associated with PDA?
Maternal/Congenital Rubella Syndrome
What percentage of congenital heart disease (CHD) cases does PDA account for?
6%-8%
What is the expected outcome of PDA in premature infants?
Spontaneous closure is common due to normal vessel anatomy of the ductus
What prevents spontaneous closure of PDA in term neonates?
Deficiency in mucoid endothelial layer and muscular media, preventing normal constriction
Why is it important to determine if a PDA patient is premature or term?
To predict the likelihood of spontaneous closure and provide appropriate counseling
When should PDA closure be maintained instead of treated?
In critical conditions such as severe pulmonary or right ventricular outflow obstruction (RVOT) where the PDA is the only source of pulmonary circulation
What are duct-dependent congenital heart diseases?
Conditions where systemic or pulmonary circulation depends on PDA patency, such as coarctation of the aorta (COA) or severe pulmonic valve stenosis/atresia
In what percentage of CHD cases does PDA serve as a source of pulmonary blood flow?
0.1
What clinical manifestations suggest a medium to large PDA?
Peripheral bounding pulses, widened pulse pressure, thrill maximal at LUSB
What happens to the PDA murmur if pulmonary vascular disease (PVD) develops?
Diastolic component may be absent, leaving only a systolic murmur
What is the characteristic murmur of PDA?
Continuous ‘machinery-like’ murmur best heard at the left upper sternal border (LUSB)
What are the classic chest X-ray findings in PDA?
Cardiomegaly, left atrial enlargement, increased pulmonary vascular markings, main pulmonary artery bulging
What are common differential diagnoses for a continuous machinery-like murmur?
Aortic-pulmonary window, ruptured sinus of Valsalva aneurysm, coronary arteriovenous fistula, truncus arteriosus with torrential pulmonary flow
Why is spontaneous PDA closure rare in term infants?
Persistent PDA beyond the first week of life is uncommon due to anatomical differences in the ductus
What are three major complications of an untreated large PDA?
Infective endarteritis, pulmonary/systemic emboli, Eisenmenger syndrome
What is the preferred treatment for PDA, regardless of age?
Catheter-based or surgical closure
When should a medium-to-large PDA be closed?
Closure should not be delayed once diagnosed to prevent complications
What is the standard treatment approach for PDA closure?
Transcatheter PDA closure
What device is used for small PDA closure?
Intravascular coils or small gap/device closure
How is a transcatheter PDA closure performed?
Approach via femoral artery to the descending aorta, reaching the ductus area for closure
What type of device is used for medium-to-large PDA closure?
Umbrella-like device
What is the embryologic abnormality in Atrioventricular Septal Defect (AVSD)?
Deficiency of the atrioventricular (AV) septum
Which genetic condition is AVSD most commonly associated with?
Down syndrome
What are the three key structural defects in AVSD?
Inlet VSD, ostium primum defect, cleft anterior mitral valve leaflet (AMVL)
What is a Gerbode shunt?
A left ventricle-to-right atrium (LV→RA) shunt due to absence of the AV septum
What is the pathophysiology of AVSD?
Left-to-right shunting at both atrial and ventricular levels
Why do AVSD patients have an early tendency to develop pulmonary vascular disease (PVD)?
High pulmonary blood flow leads to pulmonary hypertension
When is surgical correction of AVSD ideally performed?
Within 3-6 months of life, or before 1 year to prevent Eisenmenger syndrome
Why is early surgery especially crucial for AVSD patients with Down syndrome?
They have a higher tendency to develop Eisenmenger syndrome compared to non-chromosomal cases
What are the two main types of acyanotic congenital heart disease with obstructive lesions?
Pulmonary stenosis and aortic stenosis
What is the predominant ventricle in Coarctation of the Aorta (COA)?
Left ventricle (LV)
What percentage of congenital heart disease (CHD) cases does pulmonary stenosis account for?
7% to 10%
What is the most common cause of pulmonary obstruction at the valve area?
Valvar pulmonary stenosis
What syndromes are associated with pulmonary stenosis?
Noonan syndrome, LEOPARD syndrome, Alagille syndrome
What factors determine the significance of pulmonary stenosis?
Anatomic location, magnitude of lesion, patient’s age, and myocardial contractility impairment
What pathophysiologic changes occur in pulmonary stenosis?
Obstruction → increased RV systolic pressure → right ventricular hypertrophy (RVH)
What is the oxygen saturation status in pulmonary stenosis without ASD or VSD?
Normal
What is critical pulmonary stenosis in newborns characterized by?
Decreased RV compliance, right-to-left (R-L) shunt across PFO, cyanosis
What are the clinical manifestations of mild-to-moderate pulmonary stenosis?
Normal growth and developmental milestones
What are the clinical manifestations of severe pulmonary stenosis?
Right ventricular failure and cyanosis if interatrial communication is present
What is the management for moderate to severe pulmonary stenosis?
Balloon valvuloplasty or balloon valvotomy
When is open pulmonic valvuloplasty indicated?
For patients with thickened valves who cannot undergo valvotomy
What is the most common type of aortic stenosis?
Valvular aortic stenosis
What is the structural abnormality in valvular aortic stenosis?
Thickened leaflets with commissural fusion
What syndrome is associated with subvalvar aortic stenosis?
Shone syndrome (Subvalvar AoS + MS + COA)
What syndrome is associated with supravalvar aortic stenosis?
Williams syndrome
What genetic feature is common in patients with Williams syndrome?
‘Elfin’ facial appearance
What percentage of CHD cases does aortic stenosis account for?
0.05
What is the most common congenital lesion associated with aortic stenosis?
Bicuspid aortic valve
What causes a bicuspid aortic valve?
Failure of the raphe to open
What are possible complications of a bicuspid aortic valve?
Aortic stenosis or aortic regurgitation (valvular insufficiency)
What is the normal appearance of an aortic valve on imaging?
Mercedes-Benz sign (presence of 3 valve leaflets)
What are the clinical manifestations of mild-to-moderate aortic stenosis?
Asymptomatic
What are the clinical manifestations of severe aortic stenosis?
Left ventricular (LV) failure and signs of low cardiac output
What is the treatment for moderate to severe aortic stenosis?
Balloon valvuloplasty
Why is balloon valvuloplasty performed in aortic stenosis?
To prevent LV dysfunction, syncope, and sudden death
What are surgical options for severe aortic stenosis?
Konno procedure, aortic valve replacement (AVR), Ross procedure
When is surgery indicated for aortic stenosis?
For extremely dysplastic valves or subvalvar/supravalvar stenosis
What are transcatheter stent valves?
Tissue valves sewn into an expandable metal stent
In whom are transcatheter stent valves mainly used?
Adults too ill for surgery and all age groups needing stenotic area dilation
What percentage of CHD cases does coarctation of the aorta (COA) account for?
5-7%
What is the male-to-female ratio in COA?
2:1 (more common in males)
What genetic syndrome is associated with COA?
Turner syndrome
What percentage of COA patients have a bicuspid aortic valve?
More than 70%
What are intracranial vascular anomalies associated with COA?
Intracranial aneurysms
What is the usual clinical presentation of infants with COA?
Asymptomatic
What are the clinical manifestations of COA in children and adolescents?
Weakness or pain/claudication in lower extremities after exertion, hypertension on routine PE
What is the classic sign of COA on physical examination?
Disparity in pulse and blood pressure (upper extremity > lower extremity)
What is radial-femoral delay?
Delayed femoral pulse compared to radial pulse due to COA
What heart failure symptoms can occur in COA?
Systolic murmur, signs of left heart failure
What are the classic CXR findings in COA?
Figure of 3 sign and rib notching
What causes rib notching in COA?
Dilated intercostal arteries due to collateral circulation
What is the initial treatment for neonates with severe COA?
Prostaglandin E1 infusion to maintain ductus arteriosus patency
Why is prostaglandin E1 given in severe COA?
To maintain systemic circulation to lower extremities and organs
What is the definitive treatment for COA in older children?
Surgical correction or stent placement
When is stent placement preferred over surgery in COA?
In patients with severe LV dysfunction or high surgical risk
