Cardiology — MCQs
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Which of the following is the most common sustained tachyarrhythmia in children?
A 9-month-old infant accidentally ingests an unknown quantity of digitalis. What is the most important noncardiac manifestation of toxicity in this infant?
Which of the following is NOT included among the major criteria for acute rheumatic fever?
A cyanotic newborn is suspected of having congenital heart disease. The newborn has an increased left ventricular impulse and a holosystolic murmur along the left sternal border. The ECG shows left-axis deviation and left ventricular hypertrophy (LVH). Which of the following is the most likely diagnosis?
A 12-year-old girl presents with short stature, webbed neck, and widely spaced nipples, suggestive of a chromosomal abnormality confirmed by karyotyping. What is the most likely cardiovascular anomaly to be present in this child?
Which of the following statements regarding rheumatic nodules is false?
Infective endocarditis is commonly seen in all of the following conditions except?
Of the following vasculitides, coronary artery aneurysms are most often seen in which condition?
Closure of a patent ductus arteriosus in a premature infant can be stimulated by the administration of which of the following?
A newborn baby develops cyanosis on day three of life. On auscultation, there is a systolic murmur. Echocardiography reveals a cyanotic heart disease in the baby. Which one of the following drugs can be administered to prolong the life of the baby pending intervention?
Cardiology Indian Medical PG Practice Questions and MCQs
Question 161: Which of the following is the most common sustained tachyarrhythmia in children?
- A. Ventricular tachycardia
- B. Supraventricular tachycardia (Correct Answer)
- C. Atrial flutter
- D. Atrial fibrillation
Explanation: ### Explanation **Correct Answer: B. Supraventricular tachycardia (SVT)** **Why SVT is the correct answer:** Supraventricular tachycardia is the **most common symptomatic and sustained tachyarrhythmia** in the pediatric population. It is characterized by a rapid heart rate originating above the Bundle of His. In infants, the heart rate often exceeds 220 bpm, while in older children, it is typically >180 bpm. The most common underlying mechanism in children is **Atrioventricular Reentrant Tachycardia (AVRT)**, frequently associated with accessory pathways like Wolff-Parkinson-White (WPW) syndrome. **Why the other options are incorrect:** * **Ventricular Tachycardia (VT):** This is rare in children and usually associated with structural heart disease, electrolyte imbalances, or long QT syndrome. It is life-threatening but far less common than SVT. * **Atrial Flutter:** This is uncommon in children unless there is significant atrial dilation, often seen post-surgically (e.g., after Mustard or Senning procedures for Transposition of the Great Arteries). * **Atrial Fibrillation:** This is extremely rare in the pediatric age group and is generally seen only in children with severe underlying structural heart disease or dilated cardiomyopathy. **High-Yield Clinical Pearls for NEET-PG:** * **Clinical Presentation:** Infants often present with non-specific symptoms like irritability, poor feeding, and pallor. If untreated, it can lead to congestive heart failure. * **ECG Findings:** Narrow QRS complex (usually <0.08s) with absent or abnormal P-waves. * **Management:** * **Hemodynamically Unstable:** Immediate synchronized DC cardioversion (0.5–2 J/kg). * **Hemodynamically Stable:** Vagal maneuvers (e.g., ice to the face for infants) are first-line. If unsuccessful, **Adenosine** (rapid IV push) is the drug of choice. * **Long-term treatment:** Digoxin or Propropanol (Note: Digoxin is contraindicated in WPW syndrome).
Question 162: A 9-month-old infant accidentally ingests an unknown quantity of digitalis. What is the most important noncardiac manifestation of toxicity in this infant?
- A. Fever
- B. Dizziness
- C. Vomiting (Correct Answer)
- D. Visual disturbances
Explanation: **Explanation:** **Digitalis (Digoxin) toxicity** is a high-yield topic in pediatric cardiology. In infants and children, the clinical presentation differs slightly from adults, making it crucial to distinguish between cardiac and noncardiac signs. **1. Why Vomiting is the Correct Answer:** **Vomiting** is the most common and often the earliest **noncardiac** manifestation of digitalis toxicity in infants. It occurs due to the direct stimulation of the **Chemoreceptor Trigger Zone (CTZ)** in the area postrema of the medulla. Other common gastrointestinal symptoms include nausea and anorexia. In an infant, poor feeding is a frequent surrogate for these symptoms. **2. Analysis of Incorrect Options:** * **Fever (A):** Digitalis toxicity does not typically cause fever. It is more likely to cause neurological or gastrointestinal symptoms. * **Dizziness (B):** While dizziness can occur in older children or adults, it is difficult to assess in a 9-month-old infant and is not the primary diagnostic sign. * **Visual disturbances (D):** Classic "yellow-green halos" (xanthopsia) are a hallmark of digoxin toxicity in **adults**. However, these are nearly impossible to document in infants and are rarely the presenting feature in this age group. **3. High-Yield Clinical Pearls for NEET-PG:** * **Most Common Cardiac Manifestation:** In children, the most common cardiac sign is **sinus bradycardia** or **prolonged PR interval**. In adults, ventricular ectopy is more common. * **Electrolyte Interaction:** **Hypokalemia**, hypomagnesemia, and hypercalcemia predispose a patient to digoxin toxicity. * **ECG Changes:** Look for the "reverse tick" or "scooped" ST-segment depression (Digoxin effect). * **Management:** The definitive treatment for severe toxicity (arrhythmias or hyperkalemia) is **Digoxin-specific Fab fragments (Digibind).**
Question 163: Which of the following is NOT included among the major criteria for acute rheumatic fever?
- A. Erythema marginatum
- B. Chorea
- C. Polyarthralgia (Correct Answer)
- D. Pancarditis
Explanation: The diagnosis of **Acute Rheumatic Fever (ARF)** is based on the **Revised Jones Criteria**. To make a diagnosis, one requires evidence of a preceding Group A Streptococcal infection plus either two major criteria or one major and two minor criteria. ### Why Polyarthralgia is the Correct Answer **Polyarthralgia** (joint pain without objective findings) is classified as a **Minor Criterion**, not a major one. In contrast, **Polyarthritis** (objective swelling, heat, or redness in multiple joints) is a Major Criterion. It is a common "trap" in NEET-PG questions to confuse these two terms. ### Explanation of Major Criteria (Incorrect Options) The Major Criteria are remembered by the mnemonic **J♥NES**: * **J (Joints):** Migratory Polyarthritis (Option C is wrong because it lists arthralgia instead). * **♥ (Carditis):** Includes **Pancarditis** (Option D), involving the endocardium, myocardium, and pericardium. Valvulitis (especially Mitral Regurgitation) is the most common manifestation. * **N (Nodules):** Subcutaneous nodules (painless, firm, on extensor surfaces). * **E (Erythema Marginatum):** (Option A) A classic evanescent, non-pruritic pink rash with serpiginous borders. * **S (Sydenham’s Chorea):** (Option B) Involuntary, purposeless movements; it can be a standalone diagnostic feature as it often occurs after a long latent period. ### High-Yield Clinical Pearls for NEET-PG * **Minor Criteria:** Arthralgia, Fever, Elevated ESR/CRP, and Prolonged PR interval on ECG. * **Most Common Manifestation:** Migratory Polyarthritis. * **Most Serious Manifestation:** Carditis (the only one leading to chronic disability/Rheumatic Heart Disease). * **Subclinical Carditis:** Echocardiographic evidence of valvulitis without clinical murmurs is now considered a Major Criterion in high-risk populations according to the 2015 AHA revision.
Question 164: A cyanotic newborn is suspected of having congenital heart disease. The newborn has an increased left ventricular impulse and a holosystolic murmur along the left sternal border. The ECG shows left-axis deviation and left ventricular hypertrophy (LVH). Which of the following is the most likely diagnosis?
- A. Transposition of the great arteries
- B. Truncus arteriosus
- C. Tricuspid atresia (Correct Answer)
- D. Tetralogy of Fallot
Explanation: **Explanation:** The clinical presentation of a cyanotic newborn with **Left Axis Deviation (LAD)** and **Left Ventricular Hypertrophy (LVH)** on ECG is a classic "spotter" for **Tricuspid Atresia**. **Why Tricuspid Atresia is correct:** In Tricuspid Atresia, there is no communication between the right atrium and right ventricle. Systemic venous return must pass through an ASD/PFO to the left atrium and then into a dominant left ventricle. This leads to: 1. **LVH:** The left ventricle handles both systemic and pulmonary venous return. 2. **LAD:** Due to the hypoplastic right ventricle and structural conduction changes, the QRS axis shifts to the left (usually -30° to -90°). 3. **Holosystolic Murmur:** Usually represents a VSD, which is necessary for blood to reach the pulmonary circulation. **Why other options are incorrect:** * **Transposition of the Great Arteries (TGA):** Typically presents with Right Axis Deviation (RAD) and RVH. The "egg-on-a-string" appearance is seen on X-ray. * **Truncus Arteriosus:** Usually presents with increased pulmonary blood flow and biventricular hypertrophy, but the axis is typically normal or rightward. * **Tetralogy of Fallot (TOF):** The most common cyanotic heart disease, but it characteristically shows **RAD and RVH** due to right ventricular outflow obstruction and a boot-shaped heart. **High-Yield Clinical Pearls for NEET-PG:** * **Cyanotic Heart Disease + LAD =** Tricuspid Atresia (most common) or AV Canal Defect. * **ECG in Cyanotic Newborns:** Most cyanotic lesions (TOF, TGA, TAPVC) cause RAD/RVH because the right heart is under pressure. Tricuspid Atresia is the notable exception. * **X-ray finding:** Tricuspid atresia often shows a "wall-to-wall" heart or decreased pulmonary vascular markings.
Question 165: A 12-year-old girl presents with short stature, webbed neck, and widely spaced nipples, suggestive of a chromosomal abnormality confirmed by karyotyping. What is the most likely cardiovascular anomaly to be present in this child?
- A. Atrial septal defect
- B. Tetralogy of Fallot
- C. Coarctation of the aorta (Correct Answer)
- D. Patent ductus arteriosus
Explanation: **Explanation:** The clinical presentation of short stature, webbed neck, and widely spaced nipples in a female child is classic for **Turner Syndrome (45, XO)**. In Turner Syndrome, cardiovascular anomalies are present in approximately 30–50% of patients. **Why Coarctation of the aorta is correct:** The most common cardiovascular malformation in Turner Syndrome is a **Bicuspid Aortic Valve (BAV)**, occurring in about 30% of cases. However, among the options provided, **Coarctation of the Aorta (CoA)** is the hallmark association, occurring in 10–15% of patients. It typically presents as a pre-ductal or juxta-ductal narrowing. The underlying pathophysiology involves lymphatic obstruction during fetal development, which alters hemodynamics in the developing aorta. **Why other options are incorrect:** * **Atrial Septal Defect (ASD):** While common in the general population and certain syndromes like Down Syndrome (specifically ostium primum), it is not the primary association for Turner Syndrome. * **Tetralogy of Fallot (TOF):** This is the most common cyanotic heart disease but is characteristically associated with **DiGeorge Syndrome** (22q11 deletion), not Turner Syndrome. * **Patent Ductus Arteriosus (PDA):** This is most strongly associated with **Congenital Rubella Syndrome** and prematurity. **High-Yield Pearls for NEET-PG:** * **Most common cardiac anomaly in Turner Syndrome:** Bicuspid Aortic Valve (BAV). * **Most common "obstructive" lesion in Turner Syndrome:** Coarctation of the Aorta. * **Karyotype:** 45, XO is the most common, but mosaicism (45,X/46,XX) can occur. * **Other associations:** Horseshoe kidney, streak ovaries (primary amenorrhea), and increased risk of aortic dissection later in life.
Question 166: Which of the following statements regarding rheumatic nodules is false?
- A. Found over extensor surfaces
- B. Tender on palpation (Correct Answer)
- C. Associated with carditis
- D. Pea-sized nodules
Explanation: In Acute Rheumatic Fever (ARF), **Subcutaneous Nodules** are a major Jones criterion. The hallmark characteristic of these nodules is that they are **painless (non-tender)** and mobile. Therefore, the statement that they are "tender on palpation" is false. ### Explanation of Options: * **Option B (Correct):** Rheumatic nodules are characteristically **painless**. Tenderness is typically absent, which helps clinically distinguish them from other inflammatory nodules like Erythema Nodosum (which are very painful and usually located on the shins). * **Option A:** They are typically found over **extensor surfaces** of joints (elbows, knees, wrists), the occiput, or the spinous processes of the vertebrae. * **Option C:** There is a very strong clinical correlation between subcutaneous nodules and **severe carditis**. They rarely occur as an isolated finding and usually appear weeks after the onset of fever. * **Option D:** They are described as firm, symmetric, and small (ranging from a few millimeters to 2 cm), often likened to the size of a **pea**. ### High-Yield Clinical Pearls for NEET-PG: * **Jones Criteria:** Subcutaneous nodules are a **Major Criterion** but are the least common (occurring in <1–5% of cases). * **Histology:** They show a central zone of fibrinoid necrosis surrounded by histiocytes and fibroblasts (similar to Aschoff bodies but in extra-cardiac tissue). * **Duration:** They are transient, usually lasting 1–2 weeks, and do not leave permanent scars. * **Differential:** Unlike Rheumatoid nodules, Rheumatic nodules are smaller and shorter-lived.
Question 167: Infective endocarditis is commonly seen in all of the following conditions except?
- A. Small Ventricular Septal Defect (VSD)
- B. Tetralogy of Fallot (TOF)
- C. Patent Ductus Arteriosus (PDA)
- D. Atrial Septal Defect (ASD) (Correct Answer)
Explanation: **Explanation:** The risk of **Infective Endocarditis (IE)** is primarily determined by the presence of high-velocity turbulent blood flow and significant pressure gradients. These factors cause endothelial damage, leading to the deposition of fibrin and platelets (non-bacterial thrombotic endocarditis), which serve as a nidus for bacterial colonization. **Why Atrial Septal Defect (ASD) is the correct answer:** In a simple ASD (Secundum type), the pressure gradient between the left and right atrium is very low. This results in **low-velocity, laminar flow** across the defect. Because there is minimal turbulence and low shear stress, the endocardium remains intact, making IE an extremely rare complication. Therefore, ASD is the classic "except" in lists of IE-prone congenital heart diseases. **Analysis of Incorrect Options:** * **Small VSD:** Paradoxically, small VSDs (Maladie de Roger) have a higher risk of IE than large ones because they create high-velocity jets and significant turbulence against the right ventricular wall. * **Tetralogy of Fallot (TOF):** This involves high-pressure gradients (VSD and Pulmonary Stenosis), creating significant turbulence, making it a high-risk condition. * **Patent Ductus Arteriosus (PDA):** The high pressure difference between the aorta and the pulmonary artery creates a continuous high-velocity jet, frequently leading to endarteritis. **High-Yield Clinical Pearls for NEET-PG:** * **Highest Risk:** Prosthetic heart valves, prior history of IE, and cyanotic heart disease (unrepaired). * **Negligible Risk:** Secundum ASD, s/p permanent pacemakers, and isolated Mitral Valve Prolapse without regurgitation. * **Commonest Site in VSD:** The jet lesion usually occurs on the **Right Ventricular side** (where the high-pressure jet hits). * **Commonest Organism:** *Staphylococcus aureus* (Acute IE/IV drug users) and *Viridans streptococci* (Subacute IE/Post-dental procedures).
Question 168: Of the following vasculitides, coronary artery aneurysms are most often seen in which condition?
- A. Kawasaki disease (Correct Answer)
- B. Giant cell arteritis
- C. Wegener's granulomatosis
- D. Leukocytoclastic vasculitis
Explanation: **Explanation:** **Kawasaki Disease (KD)** is the correct answer because it is a systemic, medium-vessel vasculitis that has a unique predilection for the coronary arteries. It is the leading cause of acquired heart disease in children in developed nations. The underlying pathophysiology involves transmural inflammation of the coronary arteries, leading to the destruction of the muscular-elastic fiber layers, which results in **coronary artery aneurysms (CAAs)** in approximately 20–25% of untreated cases. **Analysis of Incorrect Options:** * **Giant Cell Arteritis:** A large-vessel vasculitis that typically affects the branches of the external carotid artery (e.g., temporal artery) in patients over 50. It rarely involves the coronary arteries. * **Wegener’s Granulomatosis (GPA):** A small-vessel vasculitis characterized by granulomatous inflammation of the respiratory tract and glomerulonephritis. While it can cause carditis, CAAs are not a hallmark feature. * **Leukocytoclastic Vasculitis:** A small-vessel vasculitis (hypersensitivity vasculitis) that primarily affects the skin, presenting as palpable purpura. It does not involve medium-sized muscular arteries like the coronaries. **NEET-PG High-Yield Pearls:** * **Diagnostic Criteria (CRASH and Burn):** **C**onjunctivitis (non-purulent), **R**ash (polymorphous), **A**denopathy (cervical, usually unilateral), **S**trawberry tongue (and oral mucosal changes), **H**ands/feet (edema/desquamation), and **Burn** (High-grade fever for ≥5 days). * **Treatment:** High-dose IVIG (2g/kg) and Aspirin. IVIG is most effective when given within the first 10 days to prevent CAAs. * **Investigation of Choice:** Echocardiography is used to screen for and monitor coronary artery involvement.
Question 169: Closure of a patent ductus arteriosus in a premature infant can be stimulated by the administration of which of the following?
- A. Prostaglandin analogue
- B. Estrogen
- C. Anti-estrogen compounds
- D. Prostaglandin inhibitors (Correct Answer)
Explanation: **Explanation:** **1. Why Prostaglandin Inhibitors are Correct:** In fetal life, the **Ductus Arteriosus (DA)** remains patent due to high levels of circulating **Prostaglandin E2 (PGE2)**, which is produced by the placenta and the ductal tissue itself. PGE2 acts as a potent vasodilator on the ductal smooth muscle. After birth, PGE2 levels normally drop, leading to functional closure. In premature infants, if the DA remains patent (PDA), pharmacological closure is achieved by inhibiting the enzyme **Cyclooxygenase (COX)**. This reduces prostaglandin synthesis, allowing the ductus to constrict and close. The most commonly used agents are **Indomethacin** and **Ibuprofen**. **2. Analysis of Incorrect Options:** * **A. Prostaglandin Analogue (e.g., Alprostadil):** These are used to **keep the ductus open** in neonates with ductal-dependent congenital heart diseases (e.g., Transposition of Great Arteries or Hypoplastic Left Heart Syndrome). * **B & C. Estrogen and Anti-estrogen compounds:** These hormones do not play a primary role in the acute physiological or pharmacological regulation of ductal patency or closure. **3. High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice:** **IV Ibuprofen** is currently preferred over Indomethacin due to a lower risk of necrotizing enterocolitis (NEC) and renal side effects. * **Paracetamol:** Recent evidence suggests IV Paracetamol is also effective for PDA closure with fewer side effects. * **Contraindications for NSAIDs in PDA:** Significant thrombocytopenia, bleeding diathesis, active NEC, or renal failure. * **Physical Sign:** A "Machinery-like" continuous murmur heard best at the left infraclavicular area. * **Closure Timing:** Functional closure usually occurs within 24–48 hours in term infants; anatomical closure takes 2–3 weeks.
Question 170: A newborn baby develops cyanosis on day three of life. On auscultation, there is a systolic murmur. Echocardiography reveals a cyanotic heart disease in the baby. Which one of the following drugs can be administered to prolong the life of the baby pending intervention?
- A. Indomethacin
- B. Ibuprofen
- C. Prostaglandin E1 (Correct Answer)
- D. Propranolol
Explanation: **Explanation:** The clinical presentation of a newborn developing cyanosis on day three of life suggests a **Ductal-Dependent Cyanotic Heart Disease** (e.g., Transposition of the Great Arteries, Pulmonary Atresia, or Tricuspid Atresia). In these conditions, systemic or pulmonary circulation depends on the patency of the **Ductus Arteriosus**. As the ductus begins to close physiologically within 48–72 hours of birth, the baby develops sudden, severe cyanosis. **Why Prostaglandin E1 (PGE1) is correct:** PGE1 (Alprostadil) is a potent vasodilator that prevents the closure of or reopens the Ductus Arteriosus. By maintaining a **Patent Ductus Arteriosus (PDA)**, it allows for essential mixing of oxygenated and deoxygenated blood or ensures pulmonary blood flow, stabilizing the infant until surgical intervention (like a shunt or arterial switch) can be performed. **Why the other options are incorrect:** * **Indomethacin & Ibuprofen:** These are NSAIDs that act as **Cyclooxygenase (COX) inhibitors**. They inhibit prostaglandin synthesis and are used to **close** a PDA in preterm infants. Administering these would be fatal in a ductal-dependent lesion as it would accelerate ductal closure. * **Propranolol:** This is a beta-blocker used in the management of "Tet spells" in Tetralogy of Fallot to relax the infundibular spasm; it has no role in maintaining ductal patency. **High-Yield Clinical Pearls for NEET-PG:** * **Drug of Choice for PDA closure:** Ibuprofen (preferred over Indomethacin due to fewer renal side effects). * **Side effect of PGE1 infusion:** Apnea (most common), fever, and hypotension. Always be prepared for intubation. * **Ductal-dependent systemic flow:** Coarctation of aorta, Hypoplastic Left Heart Syndrome (HLHS). * **Ductal-dependent pulmonary flow:** Pulmonary atresia, Critical pulmonary stenosis.
Practice by Chapter
Congenital Heart Diseases: Cyanotic
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Congenital Heart Diseases: Acyanotic
Practice Questions
Rheumatic Heart Disease
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Kawasaki Disease
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Infective Endocarditis
Practice Questions
Myocarditis and Cardiomyopathies
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Arrhythmias in Children
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Heart Failure in Children
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Pulmonary Hypertension
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Systemic Hypertension
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Dyslipidemia in Children
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Cardiac Evaluation and Diagnostics
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