Practice Cardiovascular System MCQs with answers designed for MBBS, FCPS, MD, and MRCPCH examinations. These case-based questions cover congenital heart disease, rheumatic heart disease, arrhythmias, heart failure, and other important pediatric cardiology topics.
MCQ NO 1: Palpitation & shortness of breath- Cardiovascular system MCQ
A 12-year-old boy presents with palpitations and shortness of breath on exertion. Six months ago, he had an episode of fever associated with joint pains. On examination, his pulse rate is 120/min, respiratory rate is 28/min, and temperature is 98.8°F. Precordial bulging is noted. Both S1 and S2 are audible, and a pansystolic murmur is heard best at the apex.
What is the most likely diagnosis?
A. Ventricular septal defect (VSD)
B. Mitral valve prolapse
C. Rheumatic heart disease
D. Infective endocarditis
E. Innocent murmur
Correct answer & Explanation:
Answer: C. Rheumatic heart disease
Explanation: Rheumatic heart disease
The history of fever and joint pains suggests a previous episode of rheumatic fever. A pansystolic murmur best heard at the apex is characteristic of mitral regurgitation, the most common valvular lesion seen in rheumatic heart disease. Patients may present months or years after the acute episode with symptoms related to valvular dysfunction, such as palpitations and exertional dyspnea.
Why not the other options?
- A. Ventricular septal defect (VSD): Typically presents in infancy with tachypnea, poor feeding, recurrent respiratory infections, and a pansystolic murmur best heard at the lower left sternal border.
- B. Mitral valve prolapse: Usually presents with a mid-systolic click and late systolic murmur. The history of rheumatic fever strongly favors rheumatic heart disease.
- D. Infective endocarditis: Commonly presents with persistent fever and systemic signs of infection, which are absent in this case.
- E. Innocent murmur: Innocent murmurs are soft, non-pathological murmurs and are not associated with symptoms such as palpitations, dyspnea, or precordial bulging.
MCQ NO 2: Heart failure- Cardiovascular system MCQ
A 3-month-old girl admitted to the Pediatric Intensive Care Unit is a known case of Ebstein anomaly and is being treated for heart failure. During your duty, the nurse reports that the infant has developed marked tachycardia. An ECG confirms supraventricular tachycardia (SVT). The child remains hemodynamically unstable despite ongoing treatment for heart failure.
What is the most appropriate initial management?
A. Carotid massage
B. Intravenous adenosine
C. Rapid verapamil infusion
D. Synchronized DC cardioversion
E. Transthoracic pacing
Correct answer & Explanation
Answer: D. Synchronized DC cardioversion
Explanation: Supraventricular tachycardia (SVT)
This infant has SVT with hemodynamic instability in the setting of underlying congenital heart disease and heart failure. The treatment of choice for unstable SVT is synchronized DC cardioversion, which should be synchronized with the QRS complex to avoid inducing ventricular fibrillation.
Why not the other options?
- A. Carotid massage: A vagal maneuver that may be attempted in stable patients but is not appropriate in an unstable infant.
- B. Intravenous adenosine: First-line pharmacologic therapy for stable SVT but should not delay cardioversion in an unstable patient.
- C. Rapid verapamil infusion: Contraindicated in infants because it may cause severe hypotension, cardiovascular collapse, and cardiac arrest.
- E. Transthoracic pacing: Primarily used for symptomatic bradyarrhythmias and has no role in the initial management of SVT.
MCQ NO 3: Pericardia effusion/ Cardiovascular system MCQ
A 9-year-old boy is admitted with a 4-week history of low-grade fever, weight loss, and progressive shortness of breath. Examination reveals elevated jugular venous pressure, muffled heart sounds, and hepatomegaly. Chest radiograph shows cardiomegaly, and echocardiography demonstrates a large pericardial effusion. Pericardial fluid analysis reveals lymphocyte predominance, high protein, and elevated ADA.
What is the most appropriate treatment?
A. ATT with steroids
B. Broad-spectrum antibiotics
C. Intravenous immunoglobulin
D. Pericardiocentesis alone
E. Prednisolone alone
Correct answer & Explanation
Correct Answer: A. ATT with steroids
Explanation
The child has tuberculous pericardial effusion. The recommended treatment is antituberculous therapy (ATT) with adjunctive corticosteroids. Pericardiocentesis is reserved for cardiac tamponade or diagnostic purposes and should not be the sole treatment.
MCQ no 4: Infective endocarditis/Cardiovascular system MCQ
A 12-year-old boy with a history of repaired tetralogy of Fallot presents with persistent fever for 10 days despite receiving intravenous ceftriaxone for presumed pneumonia. He remains febrile, and repeat blood cultures obtained before antibiotics remain sterile. Laboratory investigations show elevated CRP and ESR. Transthoracic echocardiography is inconclusive because of poor acoustic windows. Infective endocarditis is strongly suspected.
What is the most appropriate next step?
A. Add vancomycin
B. Repeat blood cultures
C. Transesophageal echocardiography
D. PET-CT scan
E. Stop antibiotics
Answer & Explanation:
Correct Answer: C. Transesophageal echocardiography
Explanation:
In patients with a high clinical suspicion of infective endocarditis and a non-diagnostic transthoracic echocardiogram, the next investigation is transesophageal echocardiography (TEE), which has much higher sensitivity for detecting vegetations, abscesses, and prosthetic valve involvement.
MCQ NO 5: Infective endocarditis/ Cardiovascular system MCQ
A 9-year-old girl with cyanotic congenital heart disease develops persistent fever and malaise. Three blood cultures grow methicillin-sensitive Staphylococcus aureus (MSSA). Echocardiography demonstrates a 12-mm vegetation on the tricuspid valve. After 7 days of appropriate intravenous antibiotics, she remains febrile, and repeat echocardiography shows an increase in vegetation size.
What is the most appropriate management?
A. Continue antibiotics
B. Add gentamicin
C. Surgical consultation
D. Change to meropenem
E. Start corticosteroids
Answer & Explanation:
Correct Answer: C. Transesophageal echocardiography
Explanation
This child has several features that strongly suggest infective endocarditis (IE):
- Repaired congenital heart disease (high-risk cardiac lesion)
- Persistent fever despite appropriate antibiotics
- Elevated inflammatory markers
- Blood cultures are negative, likely because antibiotics were started before culture results became available (culture-negative IE)
- Transthoracic echocardiography (TTE) is inconclusive
In patients with high clinical suspicion of infective endocarditis and a non-diagnostic TTE, the next investigation should be transesophageal echocardiography (TEE). TEE has a much higher sensitivity (90–100%) than TTE for detecting vegetations, valve perforation, abscesses, prosthetic valve infection, and intracardiac complications. It is particularly valuable in patients with congenital heart disease or previous cardiac surgery, where transthoracic imaging may be suboptimal.
Why the other options are incorrect
A. Add vancomycin
Incorrect.
Although vancomycin is commonly included in empirical treatment of infective endocarditis, confirmation of the diagnosis should be pursued first when TTE is inconclusive and suspicion remains high. Simply broadening antibiotic coverage without further diagnostic evaluation may expose the patient to unnecessary toxicity and does not establish the diagnosis.
B. Repeat blood cultures
Incorrect.
Repeat blood cultures are important if the patient is still febrile. However, the child has already received antibiotics, making subsequent cultures less likely to yield an organism. Since the immediate diagnostic limitation is the inconclusive echocardiogram, TEE is the preferred next investigation.
D. PET-CT scan
Incorrect.
FDG PET-CT has an established role mainly in prosthetic valve infective endocarditis and infections involving implanted cardiac devices. It is not recommended as the next investigation in native valve infective endocarditis in children, where TEE remains the investigation of choice.
E. Stop antibiotics
Incorrect.
Persistent fever in a child at high risk for infective endocarditis should never prompt discontinuation of antibiotics without establishing an alternative diagnosis. Doing so may allow progression of infection and increase the risk of complications such as heart failure, embolic events, or abscess formation.
Learning Points
- Persistent fever in a child with congenital heart disease should always raise suspicion for infective endocarditis.
- If transthoracic echocardiography is negative or inconclusive but clinical suspicion remains high, transesophageal echocardiography (TEE) is recommended.
- Blood cultures should ideally be obtained before antibiotics are started.
- Previous antibiotic therapy is a common cause of culture-negative infective endocarditis.
- TEE is significantly more sensitive than TTE for detecting vegetations and periannular complications, especially in patients with repaired congenital heart disease or prosthetic material.
MCQ NO 6: Infective endocarditis/ Cardiovascular system MCQ
A 7-year-old boy with a ventricular septal defect is admitted with persistent fever for 2 weeks. Three sets of blood cultures have been obtained before starting antibiotics. Infective endocarditis is strongly suspected based on clinical findings.
What is the most appropriate empirical antibiotic regimen while awaiting culture results?
A. Ceftriaxone
B. Meropenem
C. Penicillin G
D. Vancomycin + Ceftriaxone
E. Vancomycin alone
Correct answer & Explanation:
Correct Answer: D. Vancomycin + Ceftriaxone
Explanation
Empirical therapy should cover Staphylococcus aureus, viridans streptococci, and Enterococcus until culture results are available. A combination of vancomycin and ceftriaxone provides broad coverage.
MCQ NO 7: Infective endocarditis/ Cardiovascular system MCQ
Despite receiving appropriate intravenous antibiotics for 10 days, a 9-year-old girl with infective endocarditis continues to have high-grade fever. Repeat echocardiography shows a 16-mm mobile vegetation on the mitral valve, larger than on the initial study.
What is the most appropriate next step?
A. Continue antibiotics
B. Add gentamicin
C. Surgical consultation
D. Switch to meropenem
E. Stop antibiotics
Correct answer& Explanation:
Correct Answer: C. Surgical consultation
Explanation
Persistent infection despite appropriate antibiotics and enlarging vegetations are indications for early surgery.
MCQ NO 8: Infective endocarditis/ Cardiovascular system MCQ
A 13-year-old boy is evaluated for persistent fever and a new cardiac murmur. Echocardiography shows a vegetation on the mitral valve, but all blood cultures remain sterile. He received oral antibiotics for one week before admission.
What is the most likely reason for the negative blood cultures?
A. Fungal infection
B. Previous antibiotic therapy
C. Laboratory error
D. Viral myocarditis
E. Wrong blood culture technique
Correct answer & Explanation:
Correct Answer: B. Previous antibiotic therapy
Explanation
The most common cause of culture-negative infective endocarditis is administration of antibiotics before blood cultures are obtained.
MCQ no 9: Infective endocarditis/ Cardiovascular system MCQ
While receiving treatment for infective endocarditis, an 11-year-old boy develops worsening breathlessness. Examination reveals pulmonary edema and a newly developed severe mitral regurgitation.
What is the most appropriate management?
A. Continue antibiotics only
B. High-dose corticosteroids
C. Emergency cardiac surgery
D. Pericardiocentesis
E. Repeat blood cultures
Correct answer & Explanation: Infective endocarditis management
MCQ NO 10: Stroke with heart murmur/Cardiovascular system MCQ
A 13-year-old boy is brought to the emergency department after developing sudden weakness of the right side of his body and difficulty speaking. His parents report that he has had intermittent fever, fatigue, and loss of appetite for the past 4 weeks. On examination, he is febrile and has a previously undocumented pansystolic murmur at the apex. Urinalysis reveals 2+ proteinuria and numerous red blood cells, while serum creatinine is normal. Brain CT excludes intracranial hemorrhage.
Which of the following is the most likely diagnosis?
A. Acute rheumatic fever
B. Infective endocarditis
C. Polyarteritis nodosa
D. Systemic lupus erythematosus
E. Tuberculous meningitis
Correct answer & Explanation: Stroke with heart murmur/Cardiovascular system MCQ
Correct Answer: B. Infective endocarditis
Explanation
This child has several classical features of infective endocarditis (IE) with both embolic and immunological complications.
The important clues include:
- Prolonged fever
- Constitutional symptoms (fatigue and anorexia)
- A new cardiac murmur
- Acute ischemic stroke
- Microscopic hematuria
The stroke is most likely due to septic embolization of a fragment of valvular vegetation to the cerebral circulation. Neurological complications occur in approximately 20–40% of patients with infective endocarditis.
The hematuria is an immunological manifestation caused by immune complex-mediated glomerulonephritis, resulting in glomerular inflammation. Patients may have microscopic hematuria, proteinuria, red cell casts, and occasionally impaired renal function.
The coexistence of an embolic event (stroke) and an immune-mediated renal manifestation (hematuria) in a child with prolonged fever and a new murmur is highly suggestive of infective endocarditis.
Why the other options are incorrect
A. Acute rheumatic fever
Incorrect.
Although acute rheumatic fever may present with fever and carditis, it does not typically cause ischemic stroke due to septic emboli or immune complex glomerulonephritis resulting in hematuria.
C. Polyarteritis nodosa
Incorrect.
Polyarteritis nodosa may cause hypertension, renal disease, and neurological manifestations, but cardiac vegetations and a new murmur are not characteristic features.
D. Systemic lupus erythematosus
Incorrect.
SLE can cause stroke and nephritis with hematuria, but it is much less likely in this scenario. The prolonged fever, new murmur, and embolic phenomenon are more consistent with infective endocarditis. Although Libman-Sacks endocarditis occurs in SLE, it is usually non-infective.
E. Tuberculous meningitis
Incorrect.
Tuberculous meningitis may present with prolonged fever and focal neurological deficits due to cerebral infarction, but it does not explain the new cardiac murmur and immune-mediated hematuria.
Learning Points
- Stroke is one of the most common neurological complications of infective endocarditis and usually results from septic embolization.
- Microscopic hematuria occurs because of immune complex-mediated glomerulonephritis and is considered an immunologic manifestation of infective endocarditis.
- Embolic events, glomerulonephritis, Osler nodes, and Roth spots are classic complications tested in postgraduate examinations.
- The combination of persistent fever, new murmur, embolic stroke, and hematuria should strongly suggest infective endocarditis.