,Q1 DEMONSTRATE MASTERY OF CORE CONCEPTS
A neonate with prenatal diagnosis of d-transposition of the great arteries and
intact ventricular septum undergoes balloon atrial septostomy. Post-procedure,
the infant remains hypoxemic with PaO2 32 mmHg despite 100% oxygen. Which
hemodynamic parameter most likely explains persistent hypoxemia?
A. Restrictive atrial communication with inadequate interatrial mixing CORRECT
B. Elevated pulmonary vascular resistance limiting pulmonary blood flow
C. Systemic right ventricular dysfunction with low cardiac output
D. Persistent ductus arteriosus with left-to-right shunt
RATIONALE: In d-TGA with intact ventricular septum, survival depends on adequate interatrial
mixing. A restrictive atrial septal defect or inadequate septostomy limits mixing, causing
persistent hypoxemia despite oxygen. Elevated PVR or RV dysfunction would affect flow but are
less likely immediately post-septostomy; a PDA would not improve mixing.
Q2 DEMONSTRATE MASTERY OF CORE CONCEPTS
A patient with a Fontan circulation presents with worsening exercise tolerance and
oxygen saturations of 88%. Cardiac catheterization reveals a mean pulmonary
artery pressure of 14 mmHg, ventricular end-diastolic pressure of 8 mmHg, and a
focal stenosis in the left pulmonary artery. What is the most appropriate next step?
A. Pulmonary artery stent angioplasty CORRECT
B. Fontan conversion to extracardiac conduit
C. Pulmonary vasodilator therapy
D. Heart transplantation evaluation
RATIONALE: Focal stenosis in a Fontan pathway increases pulmonary vascular resistance and
can cause protein-losing enteropathy or decreased cardiac output. Stent angioplasty relieves the
obstruction, improving hemodynamics. Fontan conversion or transplantation are not indicated for
a discrete stenosis; vasodilators would not address the mechanical obstruction.
Page 2
,Q3 DEMONSTRATE MASTERY OF CORE CONCEPTS
Which genetic mechanism is most likely responsible for the cardiac phenotype in
a patient with a microdeletion of 22q11.2 and conotruncal anomalies?
A. Loss of TBX1 gene leading to abnormal neural crest cell migration CORRECT
B. Mutation in NKX2-5 causing septal defects
C. Deletion of elastin gene resulting in arterial stenosis
D. Abnormalities in NOTCH1 signaling causing valve malformations
RATIONALE: The 22q11.2 deletion syndrome (DiGeorge) is associated with TBX1
haploinsufficiency, which disrupts neural crest cell development, leading to conotruncal defects
like tetralogy of Fallot and interrupted aortic arch. NKX2-5 mutations cause ASD, elastin
deletions cause Williams syndrome, and NOTCH1 mutations cause bicuspid aortic valve.
Q4 DEMONSTRATE MASTERY OF CORE CONCEPTS
A 6-month-old infant with a large ventricular septal defect develops tachypnea and
poor weight gain. Which combination of hemodynamic changes is most
consistent with the development of pulmonary hypertension?
A. Decreased pulmonary vascular resistance and increased left-to-right shunt
B. Increased pulmonary vascular resistance and bidirectional shunting CORRECT
C. Decreased systemic vascular resistance and increased right-to-left shunt
D. Increased pulmonary blood flow and decreased right ventricular pressure
RATIONALE: In a large VSD, pulmonary vascular resistance may rise over time due to
pulmonary arteriolar changes. When PVR approaches systemic levels, shunting becomes
bidirectional, leading to Eisenmenger syndrome. This is a progressive process; early in life, PVR
is low and shunt is left-to-right, but sustained high flow causes remodeling.
Page 3
, Q5 DEMONSTRATE MASTERY OF CORE CONCEPTS
In a patient with hypertrophic cardiomyopathy, which finding on cardiac MRI is
most predictive of sudden cardiac death risk?
A. Extensive late gadolinium enhancement (>15% of left ventricular mass) CORRECT
B. Increased left ventricular ejection fraction
C. Presence of mitral regurgitation
D. Reduced right ventricular ejection fraction
RATIONALE: Late gadolinium enhancement on cardiac MRI reflects myocardial fibrosis. The
extent of LGE, especially >15% of LV mass, is associated with increased risk of ventricular
arrhythmias and sudden death. LVEF is often normal or hyperdynamic; MR and RVEF are not
primary SCD risk markers.
Q6 DEMONSTRATE MASTERY OF CORE CONCEPTS
A patient with a history of Kawasaki disease and giant coronary aneurysms
presents with chest pain. Which diagnostic finding is most concerning for
imminent rupture?
A. Rapid enlargement of aneurysm on serial echocardiography CORRECT
B. Thrombus within the aneurysm
C. Calcification of the aneurysm wall
D. Mild stenosis distal to the aneurysm
RATIONALE: Rapid aneurysm enlargement suggests weakening of the vessel wall and risk of
rupture. Thrombus, calcification, and stenosis are complications but do not directly indicate
imminent rupture. Serial imaging to assess size and morphology is crucial in giant aneurysms.
Page 4
A neonate with prenatal diagnosis of d-transposition of the great arteries and
intact ventricular septum undergoes balloon atrial septostomy. Post-procedure,
the infant remains hypoxemic with PaO2 32 mmHg despite 100% oxygen. Which
hemodynamic parameter most likely explains persistent hypoxemia?
A. Restrictive atrial communication with inadequate interatrial mixing CORRECT
B. Elevated pulmonary vascular resistance limiting pulmonary blood flow
C. Systemic right ventricular dysfunction with low cardiac output
D. Persistent ductus arteriosus with left-to-right shunt
RATIONALE: In d-TGA with intact ventricular septum, survival depends on adequate interatrial
mixing. A restrictive atrial septal defect or inadequate septostomy limits mixing, causing
persistent hypoxemia despite oxygen. Elevated PVR or RV dysfunction would affect flow but are
less likely immediately post-septostomy; a PDA would not improve mixing.
Q2 DEMONSTRATE MASTERY OF CORE CONCEPTS
A patient with a Fontan circulation presents with worsening exercise tolerance and
oxygen saturations of 88%. Cardiac catheterization reveals a mean pulmonary
artery pressure of 14 mmHg, ventricular end-diastolic pressure of 8 mmHg, and a
focal stenosis in the left pulmonary artery. What is the most appropriate next step?
A. Pulmonary artery stent angioplasty CORRECT
B. Fontan conversion to extracardiac conduit
C. Pulmonary vasodilator therapy
D. Heart transplantation evaluation
RATIONALE: Focal stenosis in a Fontan pathway increases pulmonary vascular resistance and
can cause protein-losing enteropathy or decreased cardiac output. Stent angioplasty relieves the
obstruction, improving hemodynamics. Fontan conversion or transplantation are not indicated for
a discrete stenosis; vasodilators would not address the mechanical obstruction.
Page 2
,Q3 DEMONSTRATE MASTERY OF CORE CONCEPTS
Which genetic mechanism is most likely responsible for the cardiac phenotype in
a patient with a microdeletion of 22q11.2 and conotruncal anomalies?
A. Loss of TBX1 gene leading to abnormal neural crest cell migration CORRECT
B. Mutation in NKX2-5 causing septal defects
C. Deletion of elastin gene resulting in arterial stenosis
D. Abnormalities in NOTCH1 signaling causing valve malformations
RATIONALE: The 22q11.2 deletion syndrome (DiGeorge) is associated with TBX1
haploinsufficiency, which disrupts neural crest cell development, leading to conotruncal defects
like tetralogy of Fallot and interrupted aortic arch. NKX2-5 mutations cause ASD, elastin
deletions cause Williams syndrome, and NOTCH1 mutations cause bicuspid aortic valve.
Q4 DEMONSTRATE MASTERY OF CORE CONCEPTS
A 6-month-old infant with a large ventricular septal defect develops tachypnea and
poor weight gain. Which combination of hemodynamic changes is most
consistent with the development of pulmonary hypertension?
A. Decreased pulmonary vascular resistance and increased left-to-right shunt
B. Increased pulmonary vascular resistance and bidirectional shunting CORRECT
C. Decreased systemic vascular resistance and increased right-to-left shunt
D. Increased pulmonary blood flow and decreased right ventricular pressure
RATIONALE: In a large VSD, pulmonary vascular resistance may rise over time due to
pulmonary arteriolar changes. When PVR approaches systemic levels, shunting becomes
bidirectional, leading to Eisenmenger syndrome. This is a progressive process; early in life, PVR
is low and shunt is left-to-right, but sustained high flow causes remodeling.
Page 3
, Q5 DEMONSTRATE MASTERY OF CORE CONCEPTS
In a patient with hypertrophic cardiomyopathy, which finding on cardiac MRI is
most predictive of sudden cardiac death risk?
A. Extensive late gadolinium enhancement (>15% of left ventricular mass) CORRECT
B. Increased left ventricular ejection fraction
C. Presence of mitral regurgitation
D. Reduced right ventricular ejection fraction
RATIONALE: Late gadolinium enhancement on cardiac MRI reflects myocardial fibrosis. The
extent of LGE, especially >15% of LV mass, is associated with increased risk of ventricular
arrhythmias and sudden death. LVEF is often normal or hyperdynamic; MR and RVEF are not
primary SCD risk markers.
Q6 DEMONSTRATE MASTERY OF CORE CONCEPTS
A patient with a history of Kawasaki disease and giant coronary aneurysms
presents with chest pain. Which diagnostic finding is most concerning for
imminent rupture?
A. Rapid enlargement of aneurysm on serial echocardiography CORRECT
B. Thrombus within the aneurysm
C. Calcification of the aneurysm wall
D. Mild stenosis distal to the aneurysm
RATIONALE: Rapid aneurysm enlargement suggests weakening of the vessel wall and risk of
rupture. Thrombus, calcification, and stenosis are complications but do not directly indicate
imminent rupture. Serial imaging to assess size and morphology is crucial in giant aneurysms.
Page 4
