Cardiology Practice Questions

Q: A newborn presents with cyanosis, tachypnea, and poor feeding within the first week of life. On examination, the infant appears lethargic with weak peripheral pulses and a single loud S2. Echocardiography reveals hypoplastic left heart structures with a small left ventricle, mitral stenosis, and aortic stenosis. What is the most likely diagnosis?

Hypoplastic Left Heart Syndrome. ***Hypoplastic Left Heart Syndrome*** - The combination of **hypoplastic left heart structures**, **small left ventricle**, **mitral stenosis**, **aortic stenosis**, and **cyanosis presenting in the neonatal period** is the hallmark of Hypoplastic Left Heart Syndrome (HLHS). - **Presentation within the first week of life** with cyanosis, poor feeding, and weak pulses occurs as the ductus arteriosus closes, leading to severely reduced systemic perfusion. - **Single loud S2** reflects the single functional semilunar valve (pulmonary valve only). - HLHS is a **ductal-dependent lesion** requiring urgent prostaglandin therapy and surgical intervention (Norwood procedure or heart transplant). *Ebstein's Anomaly* - This anomaly primarily affects the **tricuspid valve**, leading to its displacement into the right ventricle and atrialization of part of the right ventricle. - It does not involve hypoplasia of the left heart structures or stenosis of the mitral and aortic valves, as described in this patient. - Presentation is typically less severe in the neonatal period. *Total Anomalous Pulmonary Venous Return* - This condition involves the **pulmonary veins connecting abnormally** to the systemic venous circulation, rather than directly to the left atrium. - While it causes cyanosis in neonates, it does not involve hypoplastic left heart structures or the specific valvular stenoses mentioned. - Echo would show abnormal pulmonary venous drainage, not left heart hypoplasia. *Tetralogy of Fallot* - Tetralogy of Fallot is characterized by four defects: **ventricular septal defect**, **pulmonary stenosis**, **overriding aorta**, and **right ventricular hypertrophy**. - While it causes **cyanosis**, presentation is typically more gradual (weeks to months) and not as critical in the first week of life. - It does not present with hypoplastic left heart structures, mitral stenosis, or aortic stenosis.

Q: A 3-year-old girl presents with a high fever, rash, conjunctival injection, and strawberry tongue. Laboratory results reveal elevated inflammatory markers. What is the most likely diagnosis?

Kawasaki disease. ***Kawasaki disease*** - This constellation of symptoms, including **high fever**, **rash**, **conjunctival injection**, **strawberry tongue**, and **elevated inflammatory markers** in a young child, is classic for **Kawasaki disease**. - **Kawasaki disease** is a **vasculitis** that can lead to **coronary artery aneurysms** if untreated. *Scarlet fever* - While it can present with fever, rash, and **strawberry tongue**, **scarlet fever** is caused by **Streptococcus pyogenes** and typically presents with a **sore throat** and **sandpaper-like rash**, which are not mentioned here. - Conjunctival injection is not a typical feature of scarlet fever. *Measles* - **Measles** typically presents with a prodrome of **cough**, **coryza**, and **conjunctivitis** (the 3 Cs), followed by a **maculopapular rash** that spreads from the head downwards. **Koplik spots** are also characteristic. - **Strawberry tongue** is not a feature of measles. *Rubella* - **Rubella** (German measles) causes a milder illness with fever and a distinctive **macular rash** that begins on the face and spreads rapidly, often associated with **postauricular** and **occipital lymphadenopathy**. - **Conjunctival injection** and **strawberry tongue** are not characteristic findings in rubella.

Q: A 2-month-old baby presents with central cyanosis and congestive heart failure. A chest X-ray reveals cardiomegaly with an 'egg on a string' appearance. What is the most likely diagnosis?

Transposition of Great Arteries. ***Transposition of Great Arteries*** - The combination of **central cyanosis**, **congestive heart failure** in an infant, and a chest X-ray showing **cardiomegaly** with an **'egg on a string' appearance** is highly characteristic of Transposition of Great Arteries (TGA). - The **'egg on a string' appearance** specifically refers to the narrow superior mediastinum (narrow vascular pedicle due to the anteroposterior relationship of the great arteries) and an enlarged, ovoid cardiac silhouette, resembling an egg on a string. - This finding is most evident after 1-2 weeks of age when the thymus involutes. *Tetralogy of Fallot* - While it causes **cyanosis**, it typically presents with a **boot-shaped heart** on chest X-ray due to **right ventricular hypertrophy** and an upturned apex. - Patients typically experience spontaneous episodes of **cyanotic spells** ("tet spells") and often have a prominent systolic murmur due to pulmonary stenosis. - The heart size is usually normal or only mildly enlarged initially. *Ventricular Septal Defect* - This is an **acyanotic heart defect** (unless Eisenmenger syndrome develops later) and would not explain the prominent central cyanosis at 2 months of age. - A large VSD can cause congestive heart failure and cardiomegaly with increased pulmonary vascular markings, but the chest X-ray would not show the classic **'egg on a string' silhouette**. *Total Anomalous Pulmonary Venous Connection* - This condition presents with **cyanosis** and can lead to congestive heart failure, but the classic chest X-ray finding is a **'snowman' or 'figure-of-8' sign** (in supracardiac TAPVC) due to the dilated superior vena cava and left brachiocephalic vein, not an 'egg on a string'. - This appearance typically develops after several weeks to months.

Q: A 4-year-old child presents with a high fever, rash, conjunctivitis, and swelling of the hands and feet. Laboratory findings show thrombocytosis and elevated inflammatory markers. What is the most likely diagnosis?

Kawasaki disease. ***Kawasaki disease*** ✓ * This is the correct diagnosis characterized by **high fever (>5 days)**, **bilateral non-exudative conjunctivitis**, **polymorphous rash**, and **extremity changes** (swelling of hands and feet) in a young child. * **Thrombocytosis** (typically in the second week) and **elevated inflammatory markers** (ESR, CRP) are classic laboratory findings. * Kawasaki disease is a **medium-vessel vasculitis** requiring prompt treatment with **IVIG and aspirin** to prevent coronary artery aneurysms. *Scarlet fever* * Caused by **Group A Streptococcus** producing erythrogenic toxin, presenting with fever and a characteristic **fine, sandpaper-like rash**. * Key differentiators: **strawberry tongue**, **circumoral pallor**, and **Pastia's lines** in skin creases—not the prominent conjunctivitis or hand/feet swelling seen here. * Thrombocytosis is not a typical feature in the acute phase. *Measles* * Presents with **prodromal symptoms** (cough, coryza, conjunctivitis—the "3 Cs"), followed by **Koplik spots** on buccal mucosa, then a **maculopapular rash** spreading cephalocaudally. * Does **not cause extremity swelling** or significant thrombocytosis. * The rash pattern and lack of hand/feet edema distinguish it from Kawasaki disease. *Rheumatic fever* * A **delayed complication** (2-4 weeks post-infection) of Group A streptococcal pharyngitis, diagnosed using **modified Jones criteria**. * Major criteria include **carditis, migratory polyarthritis, chorea, erythema marginatum**, and **subcutaneous nodules**—none of which match this acute presentation. * Does **not present with conjunctivitis or hand/feet swelling** as primary features.

Q: A 9-year-old child presents with shortness of breath, fatigue, and a blowing systolic murmur best heard at the right upper sternal border. What is the most likely diagnosis?

Aortic stenosis. ***Aortic stenosis*** - A **blowing systolic murmur** heard best at the **right upper sternal border** is characteristic of aortic stenosis, often radiating to the neck. - In a child, symptoms like **shortness of breath** and **fatigue** suggest significant outflow obstruction, which can occur with congenital aortic valve abnormalities. *Mitral valve prolapse* - This typically presents with a **mid-systolic click** followed by a **late systolic murmur**, best heard at the apex. - While it can cause fatigue, a **blowing systolic murmur** at the right upper sternal border is not typical. *Tricuspid regurgitation* - Presents with a **holosystolic murmur** best heard at the **left lower sternal border**, which intensifies with inspiration (Carvallo's sign). - Symptoms like fatigue and shortness of breath are usually associated with right-sided heart failure. *Pulmonary stenosis* - Characterized by a **systolic ejection murmur** heard best at the **left upper sternal border**, often with a thrill and a prominent ejection click. - The murmur's location and radiation pattern differ from the right upper sternal border presentation of aortic stenosis.

Q: An infant with Down syndrome is likely to have which of the following cardiac anomalies?

Ventricular septal defect. ***Ventricular septal defect*** - **Atrioventricular septal defect (AVSD)**, also called endocardial cushion defect, is the **most common cardiac anomaly** in Down syndrome (40-45% of CHD cases), accounting for more than any other single defect. - AVSD is a **complex defect** that involves VSD, ASD, and abnormal AV valves. Since VSD is the **ventricular component of AVSD** and isolated VSDs also occur in Down syndrome, **VSD** (either as part of AVSD or isolated) is the most common ventricular pathology. - Among the options provided, **VSD is the best answer** as it represents the most frequently affected chamber septum in Down syndrome. - Clinically presents with **heart failure symptoms** and risk of **pulmonary hypertension** due to left-to-right shunting. *Atrial septal defect* - **ASDs** can occur in Down syndrome, particularly as a component of AVSD (complete or partial). - However, **isolated ASD** (especially secundum type) is less specifically associated with Down syndrome compared to the VSD component of AVSD. - While present in many Down syndrome patients with AVSD, the **ventricular component** is more hemodynamically significant. *Tetralogy of Fallot* - **Tetralogy of Fallot (TOF)** occurs in Down syndrome but with much **lower frequency** compared to AVSD. - TOF comprises: **VSD, pulmonary stenosis, right ventricular hypertrophy**, and **overriding aorta**. - Represents approximately 5-10% of CHD in Down syndrome, significantly less than AVSD. *Pulmonary atresia* - **Pulmonary atresia** is a severe cyanotic heart defect with complete obstruction of the pulmonary valve. - **Not characteristically associated** with Down syndrome; much rarer than AVSD or even TOF in this population. - Requires ductal-dependent pulmonary blood flow and urgent intervention.

Q: A 2-year-old child with no past medical history presents with fever, rash, and swelling of the hands and feet. The child appears irritable and has red, cracked lips. What is the most likely diagnosis?

Kawasaki disease. ***Kawasaki disease*** * This constellation of symptoms, including **prolonged fever (typically ≥5 days)**, rash, **swelling of hands and feet**, **red cracked lips**, and irritability, is classic for **Kawasaki disease**. * It is an acute **vasculitis** primarily affecting young children (peak age 1-5 years) and can be associated with **coronary artery aneurysms** if untreated. *Scarlet fever* * While scarlet fever presents with fever and rash, it typically causes a **sandpaper-like rash** and a **strawberry tongue**, not prominent hand/foot swelling or cracked lips. * It is caused by Group A Streptococcus and often follows a strep throat infection. *Juvenile idiopathic arthritis* * This condition primarily involves chronic joint inflammation, not acute fever and polymorphous rash. * While joint swelling can occur, the characteristic mucocutaneous findings and fever pattern are not consistent with JIA. *Hand, foot, and mouth disease* * This viral illness typically presents with fever and characteristic **vesicular lesions** on the hands, feet, and in the mouth. * The rash in the question is described as a general rash, and the prominent swelling and specific lip changes point away from Hand, Foot, and Mouth Disease.

Q: A 4-year-old boy presents with irritability, poor feeding, and failure to thrive. Physical examination reveals a loud systolic murmur. Echocardiography shows a ventricular septal defect. What is the most likely long-term complication if left untreated?

Pulmonary hypertension. ***Pulmonary hypertension*** - A large **ventricular septal defect (VSD)** causes a significant left-to-right shunt, leading to increased blood flow and pressure in the pulmonary arteries. - Over time (typically years to decades), this sustained increase in pulmonary blood flow causes irreversible remodeling of the pulmonary vasculature, leading to **pulmonary vascular obstructive disease** and **pulmonary hypertension**. - This is the **most serious long-term complication** because once established, it is **irreversible** and leads to **Eisenmenger syndrome** (shunt reversal with cyanosis), which has a very poor prognosis. - While heart failure may develop earlier, pulmonary hypertension represents the ultimate irreversible endpoint if the VSD remains uncorrected. *Heart failure* - **Congestive heart failure** is actually the **most common complication in the short-to-medium term**, and this child is already showing signs (poor feeding, failure to thrive, irritability). - However, heart failure can be managed medically and is potentially reversible with surgical correction of the VSD. - The question asks specifically about **long-term** complications, where pulmonary hypertension becomes the more critical concern due to its irreversibility. *Endocarditis* - While patients with VSD have an **increased risk of infective endocarditis** due to turbulent blood flow, this is an acute/subacute infectious complication rather than a chronic progressive process. - It occurs episodically rather than being an inevitable consequence of untreated VSD. - Risk can be mitigated with prophylactic antibiotics during high-risk procedures. *Arrhythmias* - **Arrhythmias** are not a primary complication of uncorrected VSDs in children. - They are more commonly associated with atrial septal defects, post-surgical changes, or advanced heart failure with chamber remodeling. - Not directly related to the hemodynamic consequences of left-to-right shunting.

Q: A 4-month-old infant presents with failure to thrive, a harsh systolic murmur, and signs of heart failure. What is the most likely diagnosis?

Ventricular Septal Defect. ***Ventricular Septal Defect*** - A **large ventricular septal defect** allows for significant left-to-right shunting, leading to **pulmonary overcirculation** and eventual **heart failure**, manifesting as failure to thrive and a harsh systolic murmur. - The murmur in a VSD is typically **holosystolic (pansystolic)** and loudest at the lower left sternal border. *Atrial Septal Defect* - While ASDs also cause left-to-right shunting, significant symptoms like **heart failure** and **failure to thrive** are uncommon in infancy unless the defect is very large. - The murmur associated with an ASD is typically a **systolic ejection murmur** at the upper left sternal border, often due to increased flow across the pulmonary valve, not a harsh holosystolic murmur. *Coarctation of the Aorta* - This condition presents with **differential pulses** and **blood pressure** between the upper and lower extremities, weak femoral pulses, and often a **systolic murmur** heard in the back. - While it can lead to heart failure, the primary murmur is usually not described as a generalized "harsh systolic murmur" with generalized signs of pulmonary congestion unless severe left ventricular dysfunction has occurred. *Tetralogy of Fallot* - Tetralogy of Fallot is a **cyanotic heart disease** characterized by four defects: VSD, pulmonary stenosis, overriding aorta, and right ventricular hypertrophy. - Infants typically present with **cyanosis** (blue skin) and **tet spells**, rather than predominantly heart failure symptoms and failure to thrive in the first few months of life.

Q: A 3-year-old child with a known heart murmur presents with a fever and a new heart murmur that was not previously documented. What should be the next step in management?

Echocardiography to evaluate for structural heart changes. ***Echocardiography to evaluate for structural heart changes*** - A **new heart murmur** in a febrile child with a pre-existing murmur raises concern for **infective endocarditis** or deterioration of underlying heart disease. - **Echocardiography** can visualize vegetations, assess valve function, and identify any new structural abnormalities, making it the most appropriate initial diagnostic step. *Immediate referral to a pediatric cardiologist* - While a **pediatric cardiologist** will be involved, performing an **echocardiogram** first provides critical diagnostic information needed for the specialist to make an informed management plan. - Referral alone without initial diagnostic imaging may delay necessary interventions. *Start empirical antibiotics for bacterial endocarditis* - Starting **empirical antibiotics** without confirmation could lead to unnecessary treatment, potential drug resistance, or mask the true underlying issue if it's not bacterial endocarditis. - **Blood cultures** and **echocardiography** are usually performed first to guide antibiotic therapy. *Observe and re-evaluate in 6 weeks* - This approach is inappropriate given the **fever** and **new murmur**, which are significant indicators of a potentially serious condition needing urgent evaluation. - Delaying diagnosis and treatment could lead to severe complications, especially in a child with a known heart murmur, who is at higher risk for conditions like **endocarditis**.

Question 1

A newborn presents with cyanosis, tachypnea, and poor feeding within the first week of life. On examination, the infant appears lethargic with weak peripheral pulses and a single loud S2. Echocardiography reveals hypoplastic left heart structures with a small left ventricle, mitral stenosis, and aortic stenosis. What is the most likely diagnosis?

Accepted Answer

Hypoplastic Left Heart Syndrome

Answer

Total Anomalous Pulmonary Venous Return

Answer

Ebstein's Anomaly

Answer

Tetralogy of Fallot

Question 2

A 3-year-old girl presents with a high fever, rash, conjunctival injection, and strawberry tongue. Laboratory results reveal elevated inflammatory markers. What is the most likely diagnosis?

Accepted Answer

Kawasaki disease

Answer

Scarlet fever

Answer

Measles

Answer

Rubella

Question 3

A 2-month-old baby presents with central cyanosis and congestive heart failure. A chest X-ray reveals cardiomegaly with an 'egg on a string' appearance. What is the most likely diagnosis?

Accepted Answer

Transposition of Great Arteries

Answer

Tetralogy of Fallot

Answer

Ventricular Septal Defect

Answer

Total Anomalous Pulmonary Venous Connection

Question 4

A 4-year-old child presents with a high fever, rash, conjunctivitis, and swelling of the hands and feet. Laboratory findings show thrombocytosis and elevated inflammatory markers. What is the most likely diagnosis?

Accepted Answer

Kawasaki disease

Answer

Scarlet fever

Answer

Measles

Answer

Rheumatic fever

Question 5

A 9-year-old child presents with shortness of breath, fatigue, and a blowing systolic murmur best heard at the right upper sternal border. What is the most likely diagnosis?

Accepted Answer

Aortic stenosis

Answer

Mitral valve prolapse

Answer

Tricuspid regurgitation

Answer

Pulmonary stenosis

Question 6

An infant with Down syndrome is likely to have which of the following cardiac anomalies?

Accepted Answer

Ventricular septal defect

Answer

Atrial septal defect

Answer

Tetralogy of Fallot

Answer

Pulmonary atresia

Question 7

A 2-year-old child with no past medical history presents with fever, rash, and swelling of the hands and feet. The child appears irritable and has red, cracked lips. What is the most likely diagnosis?

Accepted Answer

Kawasaki disease

Answer

Scarlet fever

Answer

Juvenile idiopathic arthritis

Answer

Hand, foot, and mouth disease

Question 8

A 4-year-old boy presents with irritability, poor feeding, and failure to thrive. Physical examination reveals a loud systolic murmur. Echocardiography shows a ventricular septal defect. What is the most likely long-term complication if left untreated?

Accepted Answer

Pulmonary hypertension

Answer

Endocarditis

Answer

Heart failure

Answer

Arrhythmias

Question 9

A 4-month-old infant presents with failure to thrive, a harsh systolic murmur, and signs of heart failure. What is the most likely diagnosis?

Accepted Answer

Ventricular Septal Defect

Answer

Atrial Septal Defect

Answer

Coarctation of the Aorta

Answer

Tetralogy of Fallot

Question 10

A 3-year-old child with a known heart murmur presents with a fever and a new heart murmur that was not previously documented. What should be the next step in management?

Accepted Answer

Echocardiography to evaluate for structural heart changes

Answer

Immediate referral to a pediatric cardiologist

Answer

Start empirical antibiotics for bacterial endocarditis

Answer

Observe and re-evaluate in 6 weeks

Cardiology — MCQs

Cardiology — MCQs

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