Cardiology — MCQs

A two-year-old boy presents with episodes of becoming dusky. On examination, there was central cyanosis and clubbing. There was no pallor, edema, or respiratory distress. The heart was normal sized with a parasternal heave. A systolic thrill was palpable over the left middle sternal border. The first heart sound was normal, and only the aortic component was audible in the second heart sound. The liver was not enlarged. What is the likely diagnosis?

Q48Medium

Which congenital heart disease most commonly causes death within the first week of life?

Q49Medium

What is true regarding secondary prophylaxis of a 6-year-old child with carditis?

Q50Medium

Which of the following statements regarding Tetralogy of Fallot is incorrect?

Cardiology Indian Medical PG Practice Questions and MCQs

Question 41: All of the following are congenital heart diseases with oligemic lung fields except?

A. Tricuspid atresia
B. Ebstein's anomaly
C. Mitral regurgitation
D. Transposition of the great arteries (TGA) (Correct Answer)

Explanation: **Explanation:** The radiological appearance of lung fields in congenital heart disease (CHD) is determined by the amount of blood reaching the pulmonary circulation. **Oligemic lung fields** (decreased pulmonary vascular markings) occur when there is an obstruction to pulmonary blood flow or a right-to-left shunt bypassing the lungs. **Why TGA is the Correct Answer:** In **Transposition of the Great Arteries (TGA)**, the pulmonary artery arises from the left ventricle. This results in **increased pulmonary blood flow** (plethoric lung fields) because the left ventricle pumps blood directly into the low-resistance pulmonary circuit. On X-ray, TGA typically presents with the classic "Egg-on-a-string" appearance due to a narrow mediastinum and cardiomegaly with plethora. **Analysis of Incorrect Options:** * **Tricuspid Atresia:** There is no communication between the right atrium and right ventricle. Blood must flow through an ASD to the left side; pulmonary flow depends on a VSD or PDA. It typically presents with **oligemic lungs** and a characteristically small right ventricle. * **Ebstein’s Anomaly:** Downward displacement of the tricuspid valve leads to "atrialization" of the right ventricle. This causes severe tricuspid regurgitation and reduced forward flow to the lungs, resulting in **oligemic lungs** and a massive "Box-shaped" heart. * **Mitral Regurgitation (Congenital):** While less common, severe right-sided obstructive lesions are the primary cause of oligemia. However, in the context of this specific MCQ, TGA is the definitive "plethoric" condition. (Note: In some contexts, severe right-to-left shunts are the focus for oligemia). **NEET-PG High-Yield Pearls:** * **Cyanotic CHD with Plethora:** TGA, TAPVC, Truncus Arteriosus, Single Ventricle. * **Cyanotic CHD with Oligemia:** Tetralogy of Fallot (TOF), Tricuspid Atresia, Ebstein’s Anomaly, Pulmonary Atresia. * **X-ray Signs:** TOF (Boot-shaped), TGA (Egg-on-string), TAPVC (Snowman/Figure of 8), Ebstein’s (Box-shaped).

Question 42: A 7-day-old baby presents to the emergency department with unconsciousness, cyanosis, and an oxygen saturation of 85%. What is the most likely diagnosis?

A. Tetralogy of Fallot
B. Transposition of the Great Arteries (TGA) (Correct Answer)
C. Total Anomalous Pulmonary Venous Connection (TAPVC)
D. Patent Ductus Arteriosus (PDA)

Explanation: **Explanation:** The clinical presentation of a neonate with profound cyanosis and unconsciousness within the first week of life is a classic indicator of a **duct-dependent cyanotic heart disease**. **1. Why TGA is the correct answer:** In **Transposition of the Great Arteries (TGA)**, the aorta arises from the right ventricle and the pulmonary artery from the left ventricle, creating two parallel circulations. Survival depends on mixing between these circuits via a Patent Ductus Arteriosus (PDA) or Foramen Ovale. As the PDA begins to close physiologically around the end of the first week (Day 7), the mixing of oxygenated and deoxygenated blood fails, leading to severe hypoxemia, cyanosis, and metabolic acidosis, which can manifest as unconsciousness or collapse. **2. Why other options are incorrect:** * **Tetralogy of Fallot (TOF):** While it is the most common cyanotic heart disease overall, it rarely presents with severe cyanosis or collapse in the first week of life because pulmonary blood flow is often maintained by the PDA or less severe stenosis initially. * **TAPVC:** Obstructive TAPVC can present early, but TGA is a more frequent cause of neonatal cyanotic collapse. Non-obstructive TAPVC usually presents later with heart failure. * **PDA:** An isolated PDA is an acyanotic condition (left-to-right shunt). It would not cause cyanosis unless associated with pulmonary hypertension (Eisenmenger syndrome), which takes years to develop. **Clinical Pearls for NEET-PG:** * **X-ray Finding:** TGA classically shows an **"Egg-on-a-string"** appearance due to a narrow mediastinum. * **Management:** The immediate treatment is **PGE1 infusion** to keep the ductus arteriosus open, followed by a Balloon Atrial Septostomy (Rashkind procedure) and eventually an **Arterial Switch Operation (Jatene procedure)**. * **Hyperoxic Test:** Used to differentiate cardiac from pulmonary cyanosis; in TGA, $PaO_2$ will not significantly rise even with 100% oxygen.

Question 43: A neonate has recurrent attacks of abdominal pain, restless irritability, and diaphoresis on feeding. Cardiac auscultation reveals a nonspecific murmur. The neonate is believed to be at risk for myocardial infarction. What is the likely diagnosis?

A. Atrial Septal Defect (ASD)
B. Ventricular Septal Defect (VSD)
C. Tetralogy of Fallot (TOF)
D. Anomalous coronary artery (Correct Answer)

Explanation: **Explanation:** The clinical presentation describes **ALCAPA (Anomalous Left Coronary Artery from the Pulmonary Artery)**, also known as **Bland-White-Garland Syndrome**. **1. Why the Correct Answer is Right:** In ALCAPA, the left coronary artery arises from the pulmonary artery instead of the aorta. As pulmonary vascular resistance drops after birth, the left ventricle receives deoxygenated blood at low pressure. Eventually, blood flows retrograde from the right coronary artery to the pulmonary artery (coronary steal). This leads to **myocardial ischemia**, especially during exertion like **feeding**. The "abdominal pain," irritability, and diaphoresis are classic signs of **infantile angina**. Without intervention, these infants are at high risk for myocardial infarction and heart failure. **2. Why Incorrect Options are Wrong:** * **ASD & VSD:** These are left-to-right shunts. While they can cause tachypnea and failure to thrive, they do not typically cause episodic, angina-like pain or early myocardial infarction. * **Tetralogy of Fallot (TOF):** Presents with cyanosis and "Tet spells" (hyperpnea and cyanosis), not typically isolated diaphoresis and irritability mimicking angina during feeding. **3. High-Yield Clinical Pearls for NEET-PG:** * **ECG Findings:** Pathological **Q-waves** in leads I, aVL, and V4–V6 (anterolateral infarct pattern). * **Chest X-ray:** Significant cardiomegaly due to left ventricular dysfunction. * **Management:** Surgical reimplantation of the anomalous artery into the aorta is the definitive treatment. * **Key Differentiator:** If a neonate presents with symptoms of **congestive heart failure + ECG evidence of infarction**, always suspect ALCAPA.

Question 44: Which of the following congenital heart diseases is associated with cyanosis, except?

A. Complete transposition of the great arteries
B. Single ventricle with or without pulmonic stenosis
C. Hypoplastic left heart
D. Atrial septal defect with mitral stenosis (Correct Answer)

Explanation: ### Explanation The core concept in pediatric cardiology is distinguishing between **Cyanotic Congenital Heart Disease (CCHD)** and **Acyanotic Congenital Heart Disease**. **Why Option D is Correct:** **Atrial Septal Defect (ASD) with Mitral Stenosis** is clinically known as **Lutembacher Syndrome**. In this condition, the mitral stenosis increases left atrial pressure, which further augments the **left-to-right shunt** through the ASD. Since oxygenated blood is moving from the left side to the right side of the heart, there is no mixing of deoxygenated blood into the systemic circulation; hence, the patient remains **acyanotic**. **Why the Other Options are Incorrect:** * **A. Complete Transposition of the Great Arteries (TGA):** This is a classic CCHD where the aorta arises from the right ventricle and the pulmonary artery from the left ventricle, creating two parallel circuits. Cyanosis is inevitable and severe. * **B. Single Ventricle:** This represents a "common mixing" lesion. Whether or not pulmonic stenosis is present, deoxygenated systemic venous return and oxygenated pulmonary venous return mix in a single chamber before being pumped to the body, causing cyanosis. * **C. Hypoplastic Left Heart Syndrome (HLHS):** This is a critical CCHD where the left-sided structures are underdeveloped. Systemic perfusion depends on the ductus arteriosus, and mixing of blood occurs at the atrial level, leading to cyanosis. **NEET-PG High-Yield Pearls:** * **Lutembacher Syndrome:** Defined as the combination of acquired Mitral Stenosis (usually rheumatic) and a congenital ASD (usually Secundum type). * **The 5 T’s of Cyanotic Heart Disease:** TGA, Tetralogy of Fallot, Truncus Arteriosus, Tricuspid Atresia, and Total Anomalous Pulmonary Venous Return (TAPVC). * **Admixture Lesions:** Single ventricle and HLHS are categorized as "mixing lesions" which always present with some degree of arterial desaturation.

Question 45: A 5-year-old boy is referred to a pediatric cardiologist after a check-up at his GP revealed he had a murmur consistent with aortic regurgitation. What is the MOST likely cause of this defect?

A. Atrial septal defect
B. Rheumatic fever
C. Cardiomyopathy
D. Ventricular septal defect (Correct Answer)

Explanation: **Explanation:** The correct answer is **Ventricular Septal Defect (VSD)**. While aortic regurgitation (AR) is classically associated with rheumatic heart disease in adults, in a pediatric patient with a congenital VSD, it occurs due to the **Venturi effect**. Subpulmonic (doubly committed) or perimembranous VSDs located just below the aortic valve create a high-velocity jet. This creates negative pressure that "sucks" the right coronary cusp of the aortic valve into the defect (valve prolapse), leading to progressive aortic regurgitation. This is a high-yield association for NEET-PG known as the **Laubry-Pezzi syndrome**. **Analysis of Incorrect Options:** * **Atrial Septal Defect (ASD):** ASDs typically present with a fixed splitting of the second heart sound (S2) and a systolic ejection murmur over the pulmonary area; they do not cause AR. * **Rheumatic Fever:** While a leading cause of acquired valvular disease (Mitral Regurgitation > Aortic Regurgitation), it is less common in a 5-year-old compared to the mechanical complications of a congenital VSD in this age group. * **Cardiomyopathy:** Dilated cardiomyopathy may cause functional mitral or tricuspid regurgitation due to annular stretching, but it is not a primary cause of isolated AR in children. **Clinical Pearls for NEET-PG:** * **Most common type of VSD:** Perimembranous. * **VSD + AR:** Most commonly seen in **Subpulmonic (Supracristal) VSDs**. * **Indication for Surgery:** The presence of even mild aortic valve prolapse or AR in a child with VSD is a strong indication for early surgical closure to prevent permanent valve damage.

Question 46: Differential cyanosis occurs in which of the following conditions?

A. Patent Ductus Arteriosus (PDA) (Correct Answer)
B. Transposition of the Great Arteries (TGA)
C. Tricuspid stenosis
D. Ventricular Septal Defect (VSD)

Explanation: **Explanation:** **Differential cyanosis** refers to a clinical state where cyanosis is present in the lower extremities but absent in the upper extremities (specifically the right arm). **Why PDA is the correct answer:** In a patient with a large **Patent Ductus Arteriosus (PDA)**, chronic left-to-right shunting leads to pulmonary hypertension and eventually **Eisenmenger syndrome** (reversal of shunt to right-to-left). Because the PDA typically joins the aorta *distal* to the origin of the left subclavian artery (or just distal to the brachiocephalic trunk), deoxygenated blood from the pulmonary artery enters the descending aorta. This results in cyanosis and clubbing of the toes, while the right upper limb remains pink (pre-ductal). **Why the other options are incorrect:** * **TGA:** Typically presents with global cyanosis. However, if a PDA is present, it can cause **Reverse Differential Cyanosis** (upper body cyanotic, lower body pink), as oxygenated blood from the LV enters the pulmonary artery and then the descending aorta via the PDA. * **Tricuspid Stenosis:** This is an obstructive right-sided lesion. If a shunt exists (like an ASD), it causes generalized cyanosis due to right-to-left shunting at the atrial level. * **VSD:** In Eisenmenger syndrome due to VSD, deoxygenated blood enters the ascending aorta, leading to uniform cyanosis in both upper and lower limbs. **High-Yield Clinical Pearls for NEET-PG:** * **Differential Cyanosis:** PDA with Eisenmenger syndrome or Coarctation of Aorta with PDA. * **Reverse Differential Cyanosis:** TGA with PDA and Pulmonary Hypertension or Supracardiac TAPVC. * **Site of PDA:** Usually located at the "isthmus" of the aorta, distal to the origin of the left subclavian artery.

Question 47: A two-year-old boy presents with episodes of becoming dusky. On examination, there was central cyanosis and clubbing. There was no pallor, edema, or respiratory distress. The heart was normal sized with a parasternal heave. A systolic thrill was palpable over the left middle sternal border. The first heart sound was normal, and only the aortic component was audible in the second heart sound. The liver was not enlarged. What is the likely diagnosis?

A. Congenital methemoglobinemia
B. Eisenmenger syndrome
C. Aortic stenosis
D. Tetralogy of Fallot (Correct Answer)

Explanation: **Explanation:** The clinical presentation is a classic description of **Tetralogy of Fallot (TOF)**, the most common cyanotic congenital heart disease (CCHD) after one year of age. **Why Tetralogy of Fallot is correct:** * **Cyanosis and Clubbing:** Indicates a right-to-left shunt. "Dusky episodes" refer to **Tet spells** (hypercyanotic spells). * **Normal Heart Size:** Unlike many other cardiac conditions, the heart in TOF is not enlarged because the right ventricle (RV) is thick-walled (hypertrophy) but not dilated. This leads to the classic **"Coeur-en-sabot" (boot-shaped heart)** on X-ray. * **Parasternal Heave:** Indicates RV hypertrophy. * **Systolic Thrill/Murmur:** The murmur in TOF is due to **Right Ventricular Outflow Tract (RVOT) obstruction** (pulmonary stenosis), not the VSD. * **Single S2:** The second heart sound is single because the pulmonary component (P2) is soft or inaudible due to the stenosed valve and posterior displacement of the pulmonary artery. Only the aortic component (A2) is heard. **Why other options are incorrect:** * **Congenital Methemoglobinemia:** Causes "chocolate-colored" cyanosis, but it would not present with a systolic thrill or a parasternal heave as it is a hematological, not structural, heart issue. * **Eisenmenger Syndrome:** This occurs due to the reversal of a left-to-right shunt (e.g., VSD/PDA). While it causes cyanosis, it typically presents with a loud, palpable P2 (pulmonary hypertension) and signs of heart failure, which are absent here. * **Aortic Stenosis:** This is an acyanotic condition. While it presents with a systolic murmur, it does not cause central cyanosis or clubbing. **High-Yield Clinical Pearls for NEET-PG:** * **Components of TOF:** VSD, Overriding of Aorta, RVOT obstruction, and RV Hypertrophy. * **The Murmur:** The intensity of the murmur is *inversely* proportional to the severity of the obstruction. * **Management of Tet Spell:** Knee-chest position (increases systemic vascular resistance), Oxygen, Morphine, and Beta-blockers (Propranolol).

Question 48: Which congenital heart disease most commonly causes death within the first week of life?

A. Ventricular septal defect (VSD)
B. Tetralogy of Fallot (TOF)
C. Ebstein's anomaly
D. Hypoplastic left ventricle (Correct Answer)

Explanation: **Explanation:** **Hypoplastic Left Heart Syndrome (HLHS)** is the most common cause of death from congenital heart disease (CHD) in the first week of life. In HLHS, the left side of the heart (mitral valve, left ventricle, and aorta) is severely underdeveloped. The systemic circulation becomes entirely dependent on the **Ductus Arteriosus (PDA)**. As the ductus begins to close physiologically within the first few days of life, the systemic perfusion fails, leading to rapid circulatory collapse, metabolic acidosis, and death if not intervened upon immediately. **Analysis of Incorrect Options:** * **Ventricular Septal Defect (VSD):** While it is the most common CHD overall, it rarely causes symptoms or death in the first week. Symptoms of heart failure typically appear at 4–6 weeks as pulmonary vascular resistance drops. * **Tetralogy of Fallot (TOF):** This is the most common *cyanotic* CHD after infancy. However, neonates are usually stable at birth unless there is severe pulmonary atresia. Death in the first week is rare. * **Ebstein’s Anomaly:** While it can cause severe right-sided failure and cyanosis in neonates, it is significantly less common than HLHS and is not the leading cause of early neonatal mortality. **High-Yield Clinical Pearls for NEET-PG:** * **Most common CHD overall:** VSD. * **Most common Cyanotic CHD (overall):** Tetralogy of Fallot. * **Most common Cyanotic CHD (at birth/neonatal period):** Transposition of the Great Arteries (TGA). * **Ductal-dependent lesions:** HLHS, Coarctation of Aorta, and TGA require Prostaglandin E1 (Alprostadil) to maintain ductal patency for survival.

Question 49: What is true regarding secondary prophylaxis of a 6-year-old child with carditis?

A. Duration of prophylaxis is lifelong
B. Duration of prophylaxis is until 18 years of age
C. Duration of prophylaxis is at least 5 years after onset
D. Duration of prophylaxis is until 25 years of age (Correct Answer)

Explanation: The secondary prophylaxis of Rheumatic Heart Disease (RHD) is a high-yield topic for NEET-PG, governed by the **Revised Jones Criteria (WHO/AHA guidelines)**. The duration of prophylaxis depends on the severity of the initial episode and the presence of residual valvular damage. ### **Explanation of the Correct Answer** In this case, the child has **Rheumatic Fever with Carditis but no residual valvular disease**. According to the guidelines: * **Carditis present, but no residual heart disease (no valvular damage):** Prophylaxis is required for **10 years or until 25 years of age**, whichever is longer. * Since the child is 6 years old, 10 years would only reach age 16. Therefore, the prophylaxis must continue until the age of **25 years** to ensure adequate protection during the period of highest risk for recurrence. ### **Analysis of Incorrect Options** * **Option A (Lifelong):** This is reserved for patients with **severe valvular disease** or those who have undergone prosthetic valve replacement. * **Option B (18 years):** This does not align with any standard RHD guideline. The minimum age for any carditis case is 25. * **Option C (5 years):** This is the duration for Rheumatic Fever **without carditis** (5 years or until age 21, whichever is longer). ### **High-Yield Clinical Pearls for NEET-PG** | Clinical Scenario | Duration of Prophylaxis | | :--- | :--- | | **RF without Carditis** | 5 years or until 21 years of age | | **RF with Carditis (No Valvular Lesion)** | 10 years or until 25 years of age | | **RF with Carditis + Persistent Valvular Disease** | 10 years or until 40 years of age (sometimes lifelong) | * **Drug of Choice:** Injection **Benzathine Penicillin G** (1.2 million units IM every 3–4 weeks). * **Oral Alternative:** Penicillin V (250 mg BD) or Erythromycin (if allergic to Penicillin).

Question 50: Which of the following statements regarding Tetralogy of Fallot is incorrect?

A. The second heart sound (S2) is single. (Correct Answer)
B. The murmur of Tetralogy of Fallot is loud.
C. Patients with Tetralogy of Fallot will develop congestive cardiac failure in the near future.
D. With age, the condition proceeds to cardiomegaly.

Explanation: **Explanation:** In Tetralogy of Fallot (TOF), the **Second Heart Sound (S2) is typically single**. This occurs because the pulmonary component (P2) is either extremely soft or absent due to severe infundibular pulmonary stenosis and the posterior displacement of the hypoplastic pulmonary artery. The audible sound is primarily the aortic component (A2), which may be loud as the aorta is "overriding" and closer to the chest wall. Therefore, Option A is a **correct statement** regarding TOF. **Analysis of other options:** * **Option B (The murmur is loud):** The characteristic murmur in TOF is a loud **ejection systolic murmur** heard at the left mid-to-upper sternal border. It is caused by flow across the right ventricular outflow tract (RVOT) obstruction, not the VSD (which is typically large and non-restrictive). * **Option C (Congestive Cardiac Failure):** This is **incorrect** for TOF. CCF is rare in TOF because the large VSD acts as a "pressure-release valve," allowing the right ventricle to shunt deoxygenated blood into the aorta. The ventricles work at systemic pressures but are not volume-overloaded. If a child with suspected TOF presents with CCF, consider an alternative diagnosis like an associated PDA or Anemia. * **Option D (Cardiomegaly):** This is also **incorrect**. TOF is classically associated with a **normal-sized heart** on X-ray. The "boot-shaped" heart (Coeur en sabot) is due to an upturned apex (RV hypertrophy) and a concave pulmonary segment, not global cardiomegaly. **Clinical Pearls for NEET-PG:** 1. **Cyanotic Spells:** Managed by Knee-chest position, Oxygen, Morphine, and Beta-blockers (Propranolol). 2. **X-ray Finding:** Boot-shaped heart with oligemic lung fields. 3. **ECG:** Right axis deviation and Right Ventricular Hypertrophy (RVH). 4. **Most common cyanotic heart disease** after the first year of life.

Practice by Chapter

Congenital Heart Diseases: Cyanotic

Practice Questions

Congenital Heart Diseases: Acyanotic

Practice Questions

Rheumatic Heart Disease

Practice Questions

Kawasaki Disease

Practice Questions

Infective Endocarditis

Practice Questions

Myocarditis and Cardiomyopathies

Practice Questions

Arrhythmias in Children

Practice Questions

Heart Failure in Children

Practice Questions

Pulmonary Hypertension

Practice Questions

Systemic Hypertension

Practice Questions

Dyslipidemia in Children

Practice Questions

Cardiac Evaluation and Diagnostics

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free

Cardiology — MCQs

Cardiology — MCQs

On this page

Practice by Chapter

Want unlimited practice?