Cardiology Practice Questions

Q: An electrocardiogram (ECG) in a patient with a systolic ejection murmur that shows an incomplete bundle branch block in the precordial lead is most consistent with which of the following conditions?

A secundum atrial septal defect (ASD).. The clinical presentation of a **systolic ejection murmur** (due to increased flow across the pulmonary valve) combined with an **incomplete right bundle branch block (RBBB)** in the precordial leads (rsR' pattern in V1) is the classic hallmark of an **Atrial Septal Defect (ASD)** [1]. **1. Why Option A is Correct:** In an **Ostium Secundum ASD** (the most common type), the volume overload of the right ventricle causes a delay in depolarization, manifesting as an incomplete RBBB [1]. Crucially, the ECG in Secundum ASD typically shows **Right Axis Deviation (RAD)**. This distinguishes it from other types of ASDs. **2. Why the Other Options are Incorrect:** * **Option C & D:** Both **Ostium Primum ASD** and **Complete AV Canal Defects** also present with an incomplete RBBB; however, they are characteristically associated with **Left Axis Deviation (LAD)** due to the superior displacement of the AV node and conduction system. * **Option B:** A **Sinus Venosus ASD** is often associated with a **leftward shift of the P-wave axis** (inverted P waves in inferior leads) because the sinoatrial node is often displaced or dysfunctional, but it does not typically present with the classic isolated incomplete RBBB/RAD pattern of a Secundum ASD. **3. High-Yield Clinical Pearls for NEET-PG:** * **Auscultation:** Look for a **fixed, wide split S2**—this is the most diagnostic physical sign of an ASD. * **ECG Shortcut:** * ASD + Right Axis Deviation = **Secundum ASD**. * ASD + Left Axis Deviation = **Primum ASD**. * **Radiology:** Chest X-ray typically shows "hilar dance" (increased pulmonary plethora) and right-sided heart enlargement [2]. * **Most Common Type:** Secundum ASD (75% of cases), located in the region of the fossa ovalis [1].

Q: A 69-year-old male, a heavy smoker (60 cigarettes/day for 40 years), presented with a 12-hour episode of slurred speech that resolved. He had a single episode of haemoptysis 4 weeks prior and has known lung cancer with brain metastases. An ECG revealed new atrial fibrillation, and all blood tests, including cardiac biomarkers, were normal. A chest CT was performed. Based on the clinical presentation and CT findings, which of the following is the most probable diagnosis?

Left atrial thrombus. ***Left atrial thrombus*** - **New atrial fibrillation** leads to blood stasis in the **left atrial appendage**, promoting thrombus formation that can embolize to cause **transient ischemic attack (TIA)**. - **Contrast-enhanced chest CT** would show a **filling defect** in the left atrial appendage, consistent with thrombus formation. *Left atrial myxoma* - **Primary cardiac tumor** that typically presents with constitutional symptoms and is **not associated with atrial fibrillation**. - Usually appears as a **mobile, pedunculated mass** attached to the **interatrial septum** on imaging, not related to new AF. *Infective endocarditis* - Would present with **fever**, **elevated inflammatory markers**, and **positive blood cultures**, which are absent in this case. - **Normal cardiac biomarkers** and lack of systemic infection signs make this diagnosis unlikely. *Rhabdomyoma* - **Benign cardiac tumor** predominantly seen in **pediatric patients** and associated with **tuberous sclerosis**. - **Multiple cardiac masses** are typical, and this tumor does not cause atrial fibrillation or embolic events.

Q: In Mitral Valve Prolapse (MVP), which of the following conditions would cause the ejection click to be more accentuated and the murmur to move closer to the first heart sound?

Marked anxiety. **Explanation** The timing of the mid-systolic click and late systolic murmur in **Mitral Valve Prolapse (MVP)** is determined by the **Left Ventricular (LV) volume**. Any maneuver that **decreases LV volume** (decreased preload or decreased afterload) causes the redundant mitral valve leaflets to prolapse earlier into the left atrium during systole [1]. This results in the click and murmur moving **closer to the first heart sound (S1)**. **1. Why Marked Anxiety is Correct:** Anxiety leads to increased sympathetic activity (tachycardia) and decreased systemic vascular resistance. Tachycardia reduces diastolic filling time, thereby **decreasing LV end-diastolic volume**. This causes the valve to reach its prolapse point earlier in systole, making the click and murmur occur sooner (closer to S1) and often louder. **2. Why the Incorrect Options are Wrong:** * **Pregnancy & Passive Leg Lifting:** Both these conditions **increase venous return (preload)**. Increased LV volume distends the ventricle, delaying the prolapse of the leaflets. This moves the click and murmur **further from S1** (closer to S2). * **Beta-blockers:** These drugs decrease heart rate and increase diastolic filling time, thereby **increasing LV volume**. Similar to leg lifting, this delays the onset of the murmur and click. **Clinical Pearls for NEET-PG:** * **The Rule of Volume:** In MVP and HOCM, maneuvers that **decrease** LV volume (Standing, Valsalva Strain) make the murmur **louder/earlier**. Maneuvers that **increase** LV volume (Squatting, Leg Raise) make the murmur **softer/later**. * **Handgrip:** Increases afterload, which increases LV volume [2], thus delaying the murmur in MVP (unlike Mitral Regurgitation, where it gets louder). * **MVP Association:** Often associated with connective tissue disorders like Marfan Syndrome and Ehlers-Danlos Syndrome.

Q: A "third heart sound" is heard in all of the following conditions EXCEPT?

Mitral stenosis. The **Third Heart Sound (S3)**, also known as a ventricular gallop, occurs during the **early diastole** (rapid ventricular filling phase) [2]. It is produced by the sudden deceleration of blood flow into a compliant or overfilled ventricle. **Why Mitral Stenosis is the Correct Answer:** In **Mitral Stenosis**, the mitral valve is narrowed and thickened [1]. This creates a physical obstruction that **restricts the rapid inflow of blood** from the atrium to the ventricle [1]. Since S3 depends on a large, rapid volume of blood hitting the ventricular wall, the restricted flow in mitral stenosis prevents its formation. Instead, mitral stenosis is characterized by an **Opening Snap** and a mid-diastolic murmur. **Analysis of Incorrect Options:** * **Athletes (Physiological S3):** In young individuals and athletes, S3 is a normal finding due to a highly compliant left ventricle that can accommodate rapid filling. * **Constrictive Pericarditis:** This produces a specific type of S3 called a **"Pericardial Knock."** It occurs because the rigid, calcified pericardium abruptly halts ventricular expansion during early diastole. * **Left Ventricular Failure:** This is a classic cause of **Pathological S3**. The ventricle is overfilled (increased end-systolic volume); when new blood enters during diastole, it strikes the residual blood and the dilated, non-compliant wall, creating the sound [2]. **High-Yield Clinical Pearls for NEET-PG:** * **S3 Timing:** Occurs just after S2, during the phase of **rapid passive ventricular filling** [2]. * **Best heard:** At the apex with the **bell** of the stethoscope (low-pitched sound) in the left lateral decubitus position. * **S4 (Atrial Gallop):** Occurs in late diastole (atrial contraction) and is always pathological, usually indicating a stiff, hypertrophied ventricle (e.g., Hypertension, Aortic Stenosis). **S4 is never heard in Atrial Fibrillation** (as there is no coordinated atrial contraction).

Q: Which of the following findings is shown in the chest leads?

Myocardial ischemia. ***Myocardial ischemia*** - Presents with **ST depression** and **T-wave inversions** in chest leads, indicating inadequate oxygen supply to myocardium. - Often seen during **stress testing** or **unstable angina**, representing reversible myocardial changes without necrosis. *Myocardial injury* - Characterized by **ST elevation** in chest leads, indicating more severe myocardial damage than ischemia. - Represents acute injury with potential for **myocardial necrosis** if not promptly treated. *Digoxin* - Shows characteristic **"reverse-tick" or "scooped" ST depression** in multiple leads, not specific to chest leads. - Associated with **shortened QT interval** and represents therapeutic digoxin effect, not pathological ischemia. *Digoxin toxicity* - Manifests primarily as **cardiac arrhythmias** like **atrial tachycardia with AV block** or **ventricular ectopy**. - ECG shows **increased automaticity** and **conduction blocks** rather than ischemic changes in chest leads.

Q: Which of the following is true about the third heart sound?

Absent in mitral stenosis. The **Third Heart Sound (S3)**, also known as the ventricular gallop, occurs during the **early diastole** (rapid ventricular filling phase). It is caused by the sudden deceleration of blood flow into a dilated, compliant ventricle [3]. ### **Why Mitral Stenosis is the Correct Answer** For an S3 to occur, there must be a rapid, unimpeded flow of blood from the atrium into the ventricle. In **Mitral Stenosis**, the narrowed valve orifice acts as a physical barrier, obstructing the rapid filling phase [2]. Therefore, S3 is characteristically **absent** in significant mitral stenosis. If an S3 is heard in a patient with suspected mitral stenosis, it suggests the presence of concomitant mitral regurgitation or an alternative diagnosis [1]. ### **Analysis of Incorrect Options** * **A. Constrictive Pericarditis:** While a "Pericardial Knock" is the classic finding here, it is essentially an early, high-pitched S3 caused by the sudden cessation of ventricular filling by a rigid pericardium. * **B. Aortic Aneurysm:** An S3 is not directly related to an aneurysm itself, but if the aneurysm causes **Aortic Regurgitation**, the resulting volume overload of the left ventricle will frequently produce an S3. * **D. Cardiac Tamponade:** In tamponade, ventricular filling is restricted throughout diastole due to high intrapericardial pressure. Heart sounds are typically **muffled or distant**, and an S3 is generally not a feature of this condition. ### **High-Yield NEET-PG Pearls** * **Physiological S3:** Normal in children, young adults, and pregnancy. * **Pathological S3:** A hallmark of **Volume Overload** (e.g., Congestive Heart Failure, Mitral Regurgitation). * **Best heard:** At the apex with the **bell** of the stethoscope in the left lateral decubitus position [1]. * **S4 (Atrial Gallop):** Occurs in late diastole; characteristically absent in **Atrial Fibrillation** (due to lack of atrial contraction).

Q: What is the most common cause of Left Ventricular Hypertrophy?

Hypertension. **Explanation:** **1. Why Hypertension is the Correct Answer:** Left Ventricular Hypertrophy (LVH) is a compensatory response to increased **afterload**. In systemic hypertension, the left ventricle must generate higher pressure to overcome the increased systemic vascular resistance [2]. According to **Laplace’s Law** (Wall Stress = Pressure × Radius / 2 × Wall Thickness), the myocardium undergoes **concentric hypertrophy** (addition of sarcomeres in parallel) to normalize wall stress. While several conditions cause LVH, hypertension is the most common cause in the general population due to its high global prevalence [1], [3]. **2. Analysis of Incorrect Options:** * **B. Aortic Stenosis:** This is a classic cause of pressure-overload LVH [2]. While it produces significant hypertrophy, it is far less common epidemiologically than systemic hypertension. * **C. Aortic Regurgitation:** This causes **volume overload**, leading to **eccentric hypertrophy** [2] (ventricular dilation with proportional wall thickening; sarcomeres added in series). It is not the most common cause of generalized LVH. * **D. Hypertrophic Obstructive Cardiomyopathy (HOCM):** This is a genetic disorder characterized by asymmetrical septal hypertrophy. It is a primary myocardial disease and is rare compared to secondary causes like hypertension. **3. Clinical Pearls for NEET-PG:** * **ECG Criteria:** The most common criteria used is the **Sokolow-Lyon Index** (S in V1 + R in V5 or V6 > 35 mm). * **Gold Standard Investigation:** Echocardiography (more sensitive than ECG). * **Concentric vs. Eccentric:** Pressure overload (HTN, AS) leads to concentric hypertrophy; Volume overload (AR, MR) leads to eccentric hypertrophy [2]. * **Reverse Remodeling:** ACE inhibitors and ARBs are the drugs of choice to help regress hypertensive LVH.

Q: A 60-year-old woman presents with a murmur suggestive of mitral stenosis and an echocardiography confirmed a mass attached to the fossa ovalis of the left atrial septum. What is the most likely diagnosis?

Cardiac myxoma. ### Explanation **Correct Answer: A. Cardiac Myxoma** **Why it is correct:** Cardiac myxoma is the most common primary cardiac tumor in adults. Approximately **75-80% occur in the left atrium**, typically attached by a pedicle to the **interatrial septum at the fossa ovalis**. The clinical presentation often mimics **mitral stenosis** because the pedunculated mass can physically obstruct the mitral valve orifice during diastole (the "wrecking ball" effect) [3]. This produces a mid-diastolic murmur [1] and sometimes a characteristic "tumor plop" heard on auscultation [3]. **Why the other options are incorrect:** * **B. Endocarditis:** Usually presents with fever, new-onset regurgitant murmurs (not stenotic), and vegetations on valve leaflets rather than a large mass on the septum [2]. * **C. Lymphoma:** Primary cardiac lymphomas are extremely rare and typically involve the right heart or cause pericardial effusions rather than a septal mass mimicking mitral stenosis. * **D. Metastatic cancer:** While more common than primary tumors, metastases (e.g., from lung, breast, or melanoma) usually involve the pericardium or myocardium and rarely present as a solitary pedunculated mass on the fossa ovalis. **NEET-PG High-Yield Pearls:** * **Triad of Myxoma:** Constitutional symptoms (fever, weight loss due to IL-6 production), Embolic phenomena, and Obstructive symptoms (mimicking mitral stenosis). * **Position Dependency:** Symptoms and murmurs may change with the patient's body position. * **Carney Complex:** An autosomal dominant syndrome (PRKAR1A mutation) featuring atrial myxomas, skin pigmentation (lentigines), and endocrine overactivity. * **Diagnosis:** Echocardiography is the gold standard for initial identification [2].

Question 1

An electrocardiogram (ECG) in a patient with a systolic ejection murmur that shows an incomplete bundle branch block in the precordial lead is most consistent with which of the following conditions?

Accepted Answer

A secundum atrial septal defect (ASD).

Answer

A sinus venosus ASD with partial anomalous pulmonary venous return (PAPVR).

Answer

An ostium primum atrial septal defect (ASD).

Answer

A complete atrioventricular canal defect.

Question 2

A 69-year-old male, a heavy smoker (60 cigarettes/day for 40 years), presented with a 12-hour episode of slurred speech that resolved. He had a single episode of haemoptysis 4 weeks prior and has known lung cancer with brain metastases. An ECG revealed new atrial fibrillation, and all blood tests, including cardiac biomarkers, were normal. A chest CT was performed. Based on the clinical presentation and CT findings, which of the following is the most probable diagnosis?

Accepted Answer

Left atrial thrombus

Answer

Left atrial myxoma

Answer

Infective endocarditis

Answer

Rhabdomyoma

Question 3

A 67-year-old man with an 18-year history of type 2 diabetes mellitus presents for a routine physical examination. His temperature is 36.9 C (98.5 F), his blood pressure is 158/98 mm Hg and his pulse is 82/minute and regular. On examination, the physician notes a non tender, pulsatile, mass in the mid-abdomen. A plain abdominal x-ray film with the patient in the lateral position reveals spotty calcification of a markedly dilated abdominal aortic wall. Following surgery, the patient is placed on a low-fat diet to reduce the risk of continued progression of his atherosclerotic disease. A bile acid sequestrant is added to interrupt enterohepatic circulation of bile acids. Which of the following agents was MOST likely prescribed?

Accepted Answer

Cholestyramine

Answer

Atorvastatin

Answer

Clofibrate

Answer

Gemfibrozil

Question 4

In Mitral Valve Prolapse (MVP), which of the following conditions would cause the ejection click to be more accentuated and the murmur to move closer to the first heart sound?

Accepted Answer

Marked anxiety

Answer

Pregnancy

Answer

Passive leg lifting in the supine position

Answer

Administration of a beta-blocker

Question 5

A "third heart sound" is heard in all of the following conditions EXCEPT?

Accepted Answer

Mitral stenosis

Answer

Athletes

Answer

Constrictive pericarditis

Answer

Left ventricular failure

Question 6

Which of the following findings is shown in the chest leads?

Accepted Answer

Myocardial ischemia

Answer

Myocardial injury

Answer

Digoxin

Answer

Digoxin toxicity

Question 7

Which of the following is true about the third heart sound?

Accepted Answer

Absent in mitral stenosis

Answer

Present in constrictive pericarditis

Answer

Absent in aortic aneurysm

Answer

Present in cardiac tamponade

Question 8

Which features favor constrictive pericarditis over restrictive cardiomyopathy?

Accepted Answer

Diastolic pressures are equalized and RV size is increased.

Answer

There is mild pericardial effusion.

Answer

Thickened pericardium is present and diastolic pressures are equalized.

Answer

Diastolic pressures are equalized and thickened pericardium is present.

Question 9

What is the most common cause of Left Ventricular Hypertrophy?

Accepted Answer

Hypertension

Answer

Aortic Stenosis

Answer

Aortic Regurgitation

Answer

Hypertrophic Obstructive Cardiomyopathy (HOCM)

Question 10

A 60-year-old woman presents with a murmur suggestive of mitral stenosis and an echocardiography confirmed a mass attached to the fossa ovalis of the left atrial septum. What is the most likely diagnosis?

Accepted Answer

Cardiac myxoma

Answer

Endocarditis

Answer

Lymphoma

Answer

Metastatic cancer to the heart

Cardiology — MCQs

Cardiology — MCQs

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