Cardiology — MCQs

A 16-day-old baby girl is brought to the emergency department appearing ill. On examination, she has pallor and dyspnea with a respiratory rate of 85 per minute. Her heart rate is 200 bpm, heart sounds are distant, and a gallop is heard. Chest X-ray shows cardiomegaly. Echocardiogram reveals dilated ventricles and dilation of the left atrium. ECG shows ventricular depolarization complexes with low voltage. What is the most likely underlying diagnosis?

Cardiology Indian Medical PG Practice Questions and MCQs

Question 371: True about a 1-year-old child with PDA is –

A. Symptoms similar to aortopulmonary window (Correct Answer)
B. Indomethacin may help in closure
C. Chances of spontaneous closure high
D. Endocarditis is rare

Explanation: ***Symptoms similar to aortopulmonary window*** - Both **patent ductus arteriosus (PDA)** and an **aortopulmonary window** involve a connection between the aorta and pulmonary artery, leading to **left-to-right shunting**. - This shunting results in similar clinical presentations, such as a **continuous murmur**, signs of **pulmonary overcirculation**, and potential for **congestive heart failure** and **pulmonary hypertension**. *Indomethacin may help in closure* - **Indomethacin** is effective in closing a PDA, but primarily in **premature infants** and typically within the first few weeks of life. - In a **1-year-old child**, the ductus arteriosus has become muscularized and fibrotic, making medical closure with indomethacin ineffective. *Chances of spontaneous closure high* - The highest probability of **spontaneous closure** of a PDA occurs within the **first few days to weeks of life**. - By **1 year of age**, spontaneous closure is highly unlikely, and the PDA is generally considered to require intervention if it is hemodynamically significant. *Endocarditis is rare* - While uncommon, **infective endocarditis** is a well-recognized complication of an uncorrected PDA. - The turbulent blood flow through the shunt creates an environment conducive to bacterial adherence and infection at the pulmonary artery end of the ductus. - This makes endocarditis a definite risk rather than a rare occurrence, particularly in untreated cases.

Question 372: Child with PDA will NOT have:

A. Necrotizing enterocolitis
B. CO₂ washout
C. Bounding pulses
D. Pulmonary hemorrhage

Explanation: This question asks which finding is NOT associated with Patent Ductus Arteriosus (PDA). *Bounding pulses* - **Bounding pulses ARE characteristically present in PDA**, not absent - Result from wide pulse pressure due to diastolic run-off from aorta to pulmonary artery - This is a classic clinical sign of hemodynamically significant PDA ***Necrotizing enterocolitis - needs verification*** - PDA CAN be associated with NEC in premature infants - "Steal phenomenon" diverts blood from splanchnic circulation - However, NEC is multifactorial and not a direct consequence of PDA ***CO₂ washout - needs verification*** - Increased pulmonary blood flow from PDA can affect ventilation - May contribute to respiratory complications - The relationship is complex and context-dependent ***Pulmonary hemorrhage - needs verification*** - Large PDA with significant left-to-right shunt increases pulmonary blood flow - Can lead to pulmonary hemorrhage, especially in preterm infants - Increased pulmonary vascular pressure and volume cause capillary damage **Note:** This question has a structural issue - all listed options except bounding pulses (which IS present in PDA) CAN occur with PDA. The question requires review for medical accuracy and clarity.

Question 373: A patient presents with cyanosis and pulmonary complications. ECG shows left axis deviation. The most likely diagnosis is:

A. TOF
B. Tricuspid atresia (Correct Answer)
C. TAPVC
D. VSD

Explanation: ***Correct Answer: Tricuspid atresia*** - Patients with **tricuspid atresia** often present with **cyanosis** due to right-to-left shunting across an atrial septal defect, and **pulmonary complications** can arise depending on pulmonary blood flow. - The ECG finding of **left axis deviation (LAD)** is highly characteristic of tricuspid atresia, as the main blood flow from the right atrium to the left atrium through the atrial septal defect leads to increased volume load on the left ventricle and left ventricular dominance. - LAD in a cyanotic neonate is virtually pathognomonic of tricuspid atresia. *Incorrect: TOF (Tetralogy of Fallot)* - While TOF causes **cyanosis** due to a right-to-left shunt, the ECG typically shows **right axis deviation** and **right ventricular hypertrophy**, not left axis deviation. - Pulmonary complications such as "tet spells" are common, but the distinctive ECG pattern (RAD, not LAD) helps differentiate it. *Incorrect: TAPVC (Total Anomalous Pulmonary Venous Connection)* - **TAPVC** presents with **cyanosis** and pulmonary edema or hypertension depending on the degree of obstruction to pulmonary venous return. - The ECG in TAPVC usually shows **right axis deviation** and **right ventricular hypertrophy** due to increased right-sided pressures, not LAD. *Incorrect: VSD (Ventricular Septal Defect)* - Isolated **VSDs** typically cause a **left-to-right shunt**, leading to pulmonary overcirculation and potentially heart failure, but **cyanosis is not a primary symptom** unless Eisenmenger syndrome develops later. - The ECG in VSD often shows **left ventricular hypertrophy** or biventricular hypertrophy depending on the size and duration of the shunt, but **left axis deviation is not a typical isolated finding** in uncomplicated VSD.

Question 374: Which of the following is NOT a ductus dependent congenital heart disease?

A. Tricuspid atresia
B. Truncus arteriosus (Correct Answer)
C. Tetralogy of Fallot with pulmonary atresia
D. Interrupted Aortic Arch

Explanation: ***Truncus arteriosus*** - In **truncus arteriosus**, a single great artery arises from both ventricles, supplying both systemic and pulmonary circulation. The **pulmonary blood flow is typically unrestricted**, meaning the ductus arteriosus is not required for survival. - While a VSD is usually present, allowing mixing of blood, the pulmonary blood flow does not depend on the **ductus arteriosus** for patency. - This is the only condition among the options that is **NOT ductus-dependent**. *Tricuspid atresia* - **Tricuspid atresia** is a ductus-dependent lesion because without a patent **ductus arteriosus**, there is inadequate mixing or blood flow to reach either the pulmonary or systemic circulation depending on the anatomic variant. - The **ductus arteriosus** is crucial for survival in the neonatal period, often necessitating prostaglandin infusion to maintain ductal patency. *Tetralogy of Fallot with pulmonary atresia* - In **TOF with pulmonary atresia**, there is complete obstruction of the right ventricular outflow tract, making the **ductus arteriosus** the only source of pulmonary blood flow. - If the **ductus arteriosus closes**, the infant will suffer from severe **cyanosis** due to complete absence of pulmonary blood flow. - Note: Standard TOF without pulmonary atresia is NOT ductus-dependent as some blood reaches the lungs through the stenotic pulmonary valve. *Interrupted Aortic Arch* - **Interrupted Aortic Arch** is a ductus-dependent lesion because postnatal survival depends on a patent **ductus arteriosus** to supply blood flow to the descending aorta and lower body. - Without the **ductus arteriosus**, the lower body lacks systemic blood supply, leading to **shock** and **organ damage**.

Question 375: Which one of the following does not produce cyanosis in the first year of life -

A. Truncus arteriosus
B. Atrial septal defect (Correct Answer)
C. Double outlet right ventricle
D. Hypoplastic left heart syndrome

Explanation: ***Atrial septal defect*** - An **atrial septal defect (ASD)** typically causes a **left-to-right shunt**, leading to increased blood flow to the lungs rather than systemic hypoxemia, thus not producing cyanosis. - Cyanosis in an ASD usually only occurs if there is significant **pulmonary hypertension** leading to shunt reversal (Eisenmenger syndrome), which is rare in the first year of life. *Truncus arteriosus* - **Truncus arteriosus** involves a single great artery arising from both ventricles, causing a mixing of systemic and pulmonary venous blood. - This mixing results in a significant amount of **deoxygenated blood** entering the systemic circulation, leading to severe cyanosis. *Double outlet right ventricle* - In **double outlet right ventricle (DORV)**, both great arteries (aorta and pulmonary artery) arise mainly from the right ventricle. - Depending on the relationship of the great arteries and the presence of a **ventricular septal defect (VSD)** location, significant deoxygenated blood can enter the systemic circulation, causing cyanosis. *Hypoplastic left heart syndrome* - **Hypoplastic left heart syndrome (HLHS)** is characterized by a severely underdeveloped left ventricle, aorta, and mitral valve. - This condition necessitates a right-to-left shunt through a patent foramen ovale or ductus arteriosus to supply systemic circulation with mixed blood, leading to severe and progressive cyanosis shortly after birth.

Question 376: All of the following about PDA are true except

A. Common heart lesion in rubella
B. More common in males (Correct Answer)
C. Treatment is closure of defect by ligation and division of ductus
D. Hypoxia and immaturity are important in maintaining the patency

Explanation: ***More common in males*** - **Patent Ductus Arteriosus (PDA)** is **more common in females** (female to male ratio of 2:1), thus this statement is incorrect. - The increased prevalence in females is thought to be due to hormonal influences during fetal development. *Common heart lesion in rubella* - PDA is indeed a **common cardiac anomaly associated with congenital rubella syndrome**, especially when infection occurs during the first trimester. - The rubella virus can interfere with the normal closure mechanisms of the ductus arteriosus. *Treatment is closure of defect by ligation and division of ductus* - **Surgical ligation and division of the ductus arteriosus** is a definitive treatment for PDA, particularly in older children or adults. - In neonates, especially premature infants, **indomethacin** (a prostaglandin inhibitor) is often the first-line treatment to induce closure. *Hypoxia and immaturity are important in maintaining the patency* - **Prematurity** is a major risk factor for PDA because the ductus arteriosus in premature infants is less responsive to oxygen-induced constriction and has immature smooth muscle. - **Hypoxia** during fetal life and immediately after birth contributes to maintaining ductal patency by preventing the usual increase in oxygen levels that triggers closure.

Question 377: In morbus caeruleus (cyanotic congenital heart defects), foramen ovale typically closes:

A. Variable depending on defect (Correct Answer)
B. 6-12 months
C. 2-3 months
D. Never

Explanation: ***Variable depending on defect*** - In **morbus caeruleus** (cyanotic congenital heart defects), the closure of the **foramen ovale** depends on the specific cardiac defect and its hemodynamics. - In defects like **tricuspid atresia**, **pulmonary atresia with intact ventricular septum**, or **severe Ebstein's anomaly**, the foramen ovale must remain patent for survival, allowing essential right-to-left shunting. - In defects like **Tetralogy of Fallot** (the most common cyanotic CHD), the foramen ovale typically closes normally as the shunt occurs at the ventricular level. - **Clinical significance:** The need for PFO patency correlates with the degree of obstruction to pulmonary blood flow at the tricuspid or pulmonary valve level. *Never* - While some cyanotic heart defects require a **patent foramen ovale (PFO)** for survival, many cyanotic defects allow normal closure. - Stating "never" is an overgeneralization that doesn't account for conditions like **Tetralogy of Fallot** where foramen ovale closure typically occurs normally. *6-12 months* - This represents the normal timeline for **anatomical closure** of the foramen ovale in healthy infants after functional closure occurs shortly after birth. - In cyanotic heart defects requiring persistent shunting, this normal timeline is disrupted, but in others (like TOF), closure may proceed on schedule. *2-3 months* - This timeframe relates to early postnatal development when functional closure has occurred and anatomical fusion is progressing. - The actual closure pattern in **morbus caeruleus** is not determined by a fixed timeline but by the underlying cardiac anatomy and hemodynamics.

Question 378: Which is the most common congenital cardiac defect?

A. Ventricular septal defect (Correct Answer)
B. Atrial septal defect
C. TAPVC
D. Transposition of great arteries

Explanation: ***Ventricular septal defect*** - **Ventricular septal defect (VSD)** is the most common form of congenital cardiac defect, occurring in approximately 2 to 6 per 1000 live births. - It involves a **hole in the septum** separating the left and right ventricles, allowing oxygenated blood to shunt from the left to the right side of the heart. *Atrial septal defect* - While common, an **atrial septal defect (ASD)** is less frequent than VSD, typically accounting for about 10% of congenital heart diseases. - It involves a **hole in the septum** between the left and right atria, leading to a left-to-right shunt. *TAPVC* - **Total anomalous pulmonary venous connection (TAPVC)** is a rare and severe congenital heart defect where all four pulmonary veins drain abnormally. - It accounts for only about 1% of all congenital cardiac defects. *Transposition of great arteries* - **Transposition of the great arteries (TGA)** is another relatively rare and critical congenital heart defect. - In TGA, the **aorta originates from the right ventricle** and the **pulmonary artery from the left ventricle**, leading to two separate circulatory systems.

Question 379: Pulmonary plethora in a child presenting with cyanosis, is seen in?

A. Coarctation of the aorta
B. Total Anomalous Pulmonary Venous Connection (TAPVC) (Correct Answer)
C. Tetralogy of Fallot (TOF)
D. Tricuspid Atresia (TA)

Explanation: ***Total Anomalous Pulmonary Venous Connection (TAPVC)*** - In **non-obstructed TAPVC**, all pulmonary veins drain anomalously into the right atrium (or its tributaries) instead of the left atrium. - This causes **complete mixing of oxygenated pulmonary venous blood with deoxygenated systemic venous blood** in the right atrium → **cyanosis**. - Since an obligatory **atrial septal defect (ASD)** allows blood to reach the left heart, and there is **increased volume load on the right heart**, there is **increased pulmonary blood flow → pulmonary plethora** on chest X-ray. - Key point: **Obstructed TAPVC** causes pulmonary venous congestion and oligemia, NOT plethora. *Coarctation of the aorta* - **Coarctation of the aorta** is an **acyanotic** congenital heart disease involving systemic outflow obstruction. - It does **not cause cyanosis** unless there is differential cyanosis (lower body only) with a PDA and pulmonary hypertension causing right-to-left shunt. - Does not cause pulmonary plethora. *Tetralogy of Fallot (TOF)* - **Tetralogy of Fallot** presents with **cyanosis** due to right-to-left shunting through a VSD. - However, it has **pulmonary oligemia (decreased pulmonary blood flow)** due to right ventricular outflow tract obstruction and pulmonary stenosis. - Chest X-ray shows **boot-shaped heart** with decreased pulmonary vascular markings, NOT plethora. *Tricuspid Atresia (TA)* - **Tricuspid atresia** causes **cyanosis** due to obligatory right-to-left shunting at the atrial level. - Pulmonary blood flow is typically **decreased or normal** (depending on presence of VSD/PDA), NOT increased. - Does not typically cause pulmonary plethora.

Question 380: A 16-day-old baby girl is brought to the emergency department appearing ill. On examination, she has pallor and dyspnea with a respiratory rate of 85 per minute. Her heart rate is 200 bpm, heart sounds are distant, and a gallop is heard. Chest X-ray shows cardiomegaly. Echocardiogram reveals dilated ventricles and dilation of the left atrium. ECG shows ventricular depolarization complexes with low voltage. What is the most likely underlying diagnosis?

A. Hypoplastic Left Heart Syndrome
B. Critical Aortic Stenosis
C. Total Anomalous Pulmonary Venous Return
D. Congestive Heart Failure secondary to congenital heart disease (Correct Answer)

Explanation: ***Congestive Heart Failure secondary to congenital heart disease*** - This is the **most appropriate answer** given the options, as it describes the clinical syndrome present in this neonate. - The findings of **dilated ventricles**, **dilated left atrium**, **low voltage ECG**, **distant heart sounds**, **gallop rhythm**, and **cardiomegaly** indicate severe cardiac dysfunction with heart failure. - While CHF is technically a presentation rather than an underlying structural diagnosis, the echo findings of **chamber dilation** (rather than hypoplasia or hypertrophy) distinguish this from the other structural heart diseases listed. - Clinical context: In neonates with dilated chambers and low voltage, consider **dilated cardiomyopathy** (from myocarditis, metabolic disease, or anomalous coronary origins), but among these options, CHF secondary to CHD is the encompassing diagnosis. *Hypoplastic Left Heart Syndrome* - HLHS involves **underdeveloped (hypoplastic)** left-sided structures, **not dilated ones** as seen in this case. - Echocardiogram would show **small/hypoplastic left ventricle** and **left atrium**, completely opposite to the dilated chambers described here. *Critical Aortic Stenosis* - Would typically show **left ventricular hypertrophy** (concentric or eccentric) rather than ventricular dilation with low voltage. - Presents with reduced cardiac output but **LV would be hypertrophied**, not dilated with low voltage as seen here. *Total Anomalous Pulmonary Venous Return* - Typically causes **right heart enlargement** and **pulmonary venous congestion** more prominently than left heart changes. - Would show **right atrial and right ventricular dilation**, not the prominent left-sided chamber dilation described in this case.

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Cardiology — MCQs

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