Cardiology Practice Questions

Q: What is true about the third heart sound (S3)?

Heard in mitral regurgitation. **Explanation:** The **third heart sound (S3)**, also known as a ventricular gallop, occurs during the **early phase of diastole** (rapid ventricular filling phase) [2]. It is caused by the sudden deceleration of blood flow into a dilated or non-compliant left ventricle. **1. Why Option A is Correct:** In **Mitral Regurgitation (MR)**, there is a volume overload of the left ventricle. During diastole, the ventricle receives both the normal venous return and the regurgitated volume from the previous systole. This massive influx of blood into a dilated ventricle creates the S3 [4]. It is a hallmark of volume overload states and heart failure. **2. Why the Other Options are Incorrect:** * **Option B:** S3 is a **diastolic sound**, occurring just after S2. Systolic sounds include S1 and ejection clicks [3]. * **Option C:** S3 is a **low-pitched sound** (thud-like) [1]. It is best heard with the **bell** of the stethoscope at the apex in the left lateral decubitus position [1]. High-pitched sounds (like S1, S2, or MR murmurs) are heard better with the diaphragm. * **Option D:** While S3 can be physiological in children, young adults (<40 years), and pregnant women, it is **pathological in older adults**, where it usually signifies congestive heart failure (CHF). **Clinical Pearls for NEET-PG:** * **S3 Sequence:** S1–S2–S3 (resembles the cadence of the word "Kentucky"). * **Most Common Cause:** Left ventricular failure (decreased EF). * **Differential Diagnosis:** S3 is also seen in high-output states like anemia, thyrotoxicosis, and pregnancy. * **S4 vs. S3:** S4 (atrial gallop) occurs in late diastole and is associated with **pressure overload** (e.g., Hypertension, Aortic Stenosis) and stiff ventricles.

Q: A 30-year-old female presented with eclampsia. After 3 hours of admission, she is complaining of palpitations for which an ECG was performed. Vitals are stable. What is the next best management?

Magnesium sulfate. ***Magnesium sulfate*** - **Torsades de Pointes (TdP)** is polymorphic ventricular tachycardia often seen in eclampsia due to **electrolyte disturbances**, and **IV magnesium sulfate** is the first-line treatment for hemodynamically stable patients. - Magnesium helps **stabilize cardiac membranes** and corrects the underlying **QT prolongation** that predisposes to TdP. *DC shock* - **DC cardioversion** is reserved for **hemodynamically unstable** patients with TdP or ventricular fibrillation. - Since the patient has **stable vitals**, electrical cardioversion is not the immediate first-line treatment. *Amiodarone* - **Prolongs QT interval** and can actually **worsen TdP** by further increasing the risk of polymorphic VT. - Contraindicated in **TdP management** as it may precipitate more arrhythmic episodes. *Adenosine* - Effective for **supraventricular tachycardia (SVT)** by blocking AV nodal conduction temporarily. - **Not effective for ventricular tachycardia** like TdP, as it does not address the underlying ventricular origin of the arrhythmia.

Q: What is the treatment for orthostatic hypotension?

Fludrocortisone. **Explanation:** Orthostatic hypotension (OH) is defined as a sustained reduction in systolic blood pressure of at least 20 mmHg or diastolic blood pressure of 10 mmHg within 3 minutes of standing [1]. The primary goal of treatment is to increase intravascular volume and peripheral vascular resistance. **Why Fludrocortisone is correct:** **Fludrocortisone** is a potent synthetic mineralocorticoid and the first-line pharmacological treatment for symptomatic OH [2]. It works by promoting renal sodium reabsorption, thereby expanding the extracellular fluid volume and increasing the sensitivity of alpha-adrenergic receptors to circulating catecholamines, which enhances vasoconstriction. **Why the other options are incorrect:** * **Dopamine (A):** This is an intravenous inotrope/vasopressor used in acute shock or critical care settings. It is not practical or indicated for the chronic management of orthostatic hypotension. * **Diuretics (B):** These agents (e.g., Furosemide) promote fluid loss and decrease blood volume, which would significantly worsen orthostatic hypotension [3]. * **Calcium Channel Blockers (D):** These drugs (e.g., Amlodipine) cause peripheral vasodilation and are used to treat hypertension; they would exacerbate the drop in blood pressure upon standing. **High-Yield Clinical Pearls for NEET-PG:** * **Non-pharmacological measures:** Always the first step (e.g., increasing salt/water intake [2], using compression stockings, and avoiding sudden postural changes). * **Midodrine:** An alpha-1 agonist often used as a second-line agent or in combination with fludrocortisone. * **Droxidopa:** A precursor of norepinephrine used specifically in neurogenic orthostatic hypotension (e.g., Parkinson’s, MSA). * **Side effect alert:** Monitor for hypokalemia and supine hypertension when using Fludrocortisone.

Q: Dressler's syndrome is due to:

Myocardial infarction. **Explanation:** **Dressler’s Syndrome** (also known as post-myocardial infarction syndrome) is a form of secondary **pericarditis** that occurs as a late complication following a **Myocardial Infarction (MI)**. 1. **Why Myocardial Infarction is correct:** The underlying mechanism is an **immune-mediated (Type III hypersensitivity)** response. Following an MI, cardiac antigens are released into the circulation due to myocardial necrosis. The body forms anti-myocardial antibodies, leading to an inflammatory reaction involving the pericardium, pleura, and sometimes the lungs. It typically presents **2 to 6 weeks** after the acute event with fever, pleuritic chest pain, and pericardial effusion. 2. **Why the other options are incorrect:** * **Cor pulmonale:** This refers to right-sided heart failure due to chronic lung disease (e.g., COPD). It does not trigger the specific autoimmune pericarditis seen in Dressler’s. * **Mitral stenosis:** This is a valvular heart disease. While it leads to left atrial enlargement and pulmonary congestion, it is not an inflammatory or necrotic trigger for post-cardiac injury syndrome. * **Pulmonary embolism:** While PE can cause pleuritic chest pain and pleural effusion, it does not cause the systemic autoimmune pericarditis characteristic of Dressler’s syndrome. **High-Yield Clinical Pearls for NEET-PG:** * **Timeline:** Unlike "Early Post-infarction Pericarditis" (which occurs within 1–3 days due to direct inflammation), Dressler’s is a **late** complication (weeks later). * **Triad:** Fever, pleurisy, and pericardial effusion. * **Treatment:** The mainstay of treatment is **Aspirin** or **NSAIDs** plus **Colchicine**. Steroids are reserved for refractory cases [1]. * **ECG Finding:** Diffuse ST-segment elevation with PR-segment depression (typical of pericarditis) [1].

Q: What is the relationship between the S1 ejection click and severe pulmonary stenosis?

In severe pulmonary stenosis, the gap reduces.. **Explanation:** The **pulmonary ejection click** occurs due to the sudden tensing of the stenotic pulmonary valve leaflets as they reach their maximum excursion during ventricular systole. The timing of this click is determined by the pressure in the right ventricle (RV) relative to the pulmonary artery (PA). **1. Why the gap reduces (Correct Answer):** In **severe pulmonary stenosis**, the RV pressure rises much more rapidly during early systole to overcome the high resistance of the valve. Because the RV pressure reaches the opening threshold (PA diastolic pressure) much earlier, the valve opens sooner after the first heart sound (S1). Consequently, the interval between S1 and the ejection click shortens. In extremely severe cases, the click may even merge with S1 or disappear. **2. Analysis of Incorrect Options:** * **Option A:** An increased gap is seen in **mild pulmonary stenosis**, where RV pressure rises more slowly, delaying the opening of the valve. * **Option C:** The timing of the click is dynamic and directly correlates with the severity of the pressure gradient. * **Option D:** The ejection click is a systolic event; it cannot occur before S1 (which marks the beginning of systole). **High-Yield Clinical Pearls for NEET-PG:** * **The Respiratory Paradox:** The pulmonary ejection click is the **only** right-sided sound that **decreases in intensity during inspiration**. This happens because increased venous return during inspiration raises RV end-diastolic pressure, causing the valve to "float" upward prematurely, reducing its excursion during systole. * **Severity Markers:** As PS severity increases: 1. The S1-Click interval **decreases**. 2. The systolic murmur becomes **longer** and peaks **later** in systole. 3. The S2 split becomes **wider** (delayed P2) and the P2 component becomes **softer**.

Q: What is the initial pharmacological treatment for sinus bradycardia in the context of myocardial infarction?

Atropine. **Explanation:** **Why Atropine is the Correct Answer:** Sinus bradycardia is common in the early stages of acute myocardial infarction (MI), particularly in **inferior wall MI**, due to increased vagal tone or ischemia of the SA node. [3] **Atropine** is the first-line pharmacological treatment because it is a competitive antagonist of acetylcholine at muscarinic receptors. By blocking vagal inhibition, it increases the heart rate and improves cardiac output. It is indicated if the bradycardia is symptomatic (e.g., hypotension, altered mental status, or ischemic chest pain). [3] **Why the Other Options are Incorrect:** * **B. Digoxin:** This is a positive inotrope but a negative chronotrope. It increases vagal tone and slows the heart rate, which would worsen bradycardia. * **C. Calcium Channel Blockers (e.g., Verapamil, Diltiazem):** These agents have negative chronotropic and dromotropic effects. They are contraindicated in bradycardia as they further suppress the SA and AV nodes. [1] * **D. Propranolol:** This is a non-selective beta-blocker. [2] Beta-blockers decrease the heart rate and are contraindicated in the acute phase of MI if the patient is already bradycardic or has heart block. [1] **Clinical Pearls for NEET-PG:** * **Drug of Choice:** Atropine (0.5 mg IV, repeatable up to 3 mg) is the initial drug for symptomatic bradycardia. [3] * **Inferior Wall MI Connection:** Sinus bradycardia is most frequently associated with Inferior MI (Right Coronary Artery occlusion) due to the **Bezold-Jarisch reflex**. [3] * **Next Step:** If Atropine fails, the next steps include transcutaneous pacing or infusions of Dopamine or Epinephrine. [3] * **Caution:** Use Atropine cautiously in MI; excessive increases in heart rate can increase myocardial oxygen demand and worsen ischemia.

Q: A 45-year-old man presents with central chest pain for 4 hours. Troponin I is 0.8 ng/dL. What is the diagnosis?

Anterior wall, NSTEMI. ***Anterior wall, NSTEMI*** - **Elevated troponin I (0.8 ng/dL)** indicates myocardial necrosis, confirming myocardial infarction rather than unstable angina. - **Anterior wall localization** suggests involvement of **LAD territory** with likely **ST depression or T-wave inversions in V1-V4** without ST elevation, characteristic of NSTEMI. *Anterior wall, STEMI* - Would require **ST elevation ≥1mm in V1-V4** on ECG, which is not mentioned in this case. - **Troponin elevation** alone without ST elevation cannot diagnose STEMI. *Unstable Angina* - Characterized by **normal cardiac biomarkers** including troponin levels within normal range. - **Elevated troponin I (0.8 ng/dL)** definitively rules out unstable angina and confirms myocardial infarction. *Prinzmetal angina* - Caused by **coronary artery vasospasm** typically occurring at rest, often with **transient ST elevation**. - **Troponin levels remain normal** as there is no myocardial necrosis in typical vasospastic episodes.

Q: Which type of Atrial Septal Defect (ASD) is associated with a murmur similar to Mitral Regurgitation (MR) and left axis deviation?

ASD primum. **Explanation:** **ASD primum** (a type of partial Atrioventricular Septal Defect) is the correct answer due to its unique anatomical and electrophysiological characteristics: 1. **Mitral Regurgitation (MR) Murmur:** ASD primum is almost universally associated with a **cleft in the anterior mitral leaflet**. This cleft results in mitral regurgitation, which produces a holosystolic murmur at the apex radiating to the axilla, mimicking isolated MR. 2. **Left Axis Deviation (LAD):** In most ASDs (like secundum), the axis is shifted to the right. However, in ASD primum, there is a congenital displacement of the AV node and the bundle of His. This leads to early activation of the left ventricle, resulting in a characteristic **Left Axis Deviation** on ECG (often -30° to -90°). **Analysis of Incorrect Options:** * **ASD secundum (A):** The most common type of ASD. It typically presents with **Right Axis Deviation (RAD)** and a Right Bundle Branch Block (RBBB) pattern. It does not involve the mitral valve. * **Floppy mitral valve (C):** While this causes MR, it is not an atrial septal defect and does not typically present with the specific ECG findings or shunting associated with ASDs. * **ASD secundum with rheumatic MR (D):** Known as **Lutembacher Syndrome** (classically MS, but can include MR). While it features both an ASD and a murmur, it does not explain the congenital LAD seen in primum defects. **High-Yield Clinical Pearls for NEET-PG:** * **ASD primum** is strongly associated with **Down Syndrome** (Trisomy 21). * **ECG Triad for ASD Primum:** Prolonged PR interval (1st-degree heart block), Left Axis Deviation, and RBBB. * **Physical Exam:** Look for a "fixed wide split S2" (common to all ASDs) PLUS an apical holosystolic murmur (unique to primum).

Question 1

What is true about the third heart sound (S3)?

Accepted Answer

Heard in mitral regurgitation

Answer

A systolic sound

Answer

A high-pitched sound

Answer

Normal in adults

Question 2

A 30-year-old female presented with eclampsia. After 3 hours of admission, she is complaining of palpitations for which an ECG was performed. Vitals are stable. What is the next best management?

Accepted Answer

Magnesium sulfate

Answer

DC shock

Answer

Amiodarone

Answer

Adenosine

Question 3

What is the treatment for orthostatic hypotension?

Accepted Answer

Fludrocortisone

Answer

Dopamine

Answer

Diuretics

Answer

Calcium channel blockers

Question 4

Dressler's syndrome is due to:

Accepted Answer

Myocardial infarction

Answer

Cor pulmonale

Answer

Mitral stenosis

Answer

Pulmonary embolism

Question 5

What is the relationship between the S1 ejection click and severe pulmonary stenosis?

Accepted Answer

In severe pulmonary stenosis, the gap reduces.

Answer

In severe pulmonary stenosis, the gap increases.

Answer

In severe pulmonary stenosis, there is no change.

Answer

In severe pulmonary stenosis, the ejection click comes before.

Question 6

What is the initial pharmacological treatment for sinus bradycardia in the context of myocardial infarction?

Accepted Answer

Atropine

Answer

Digoxin

Answer

Calcium channel blocker

Answer

Propranolol

Question 7

Which of the following statements is TRUE in diastolic dysfunction of the left ventricle?

Accepted Answer

Tachycardia will improve the symptoms

Answer

It presents as dyspnea on exertion

Answer

Uncontrolled hypertension is an important cause

Answer

Ischemic heart disease is a cause

Question 8

The ECG given below is seen in which condition?

Accepted Answer

Heart failure

Answer

Hyperkalemia

Answer

Hypothermia

Answer

Pericarditis

Question 9

A 45-year-old man presents with central chest pain for 4 hours. Troponin I is 0.8 ng/dL. What is the diagnosis?

Accepted Answer

Anterior wall, NSTEMI

Answer

Anterior wall, STEMI

Answer

Unstable Angina

Answer

Prinzmetal angina

Question 10

Which type of Atrial Septal Defect (ASD) is associated with a murmur similar to Mitral Regurgitation (MR) and left axis deviation?

Accepted Answer

ASD primum

Answer

ASD secundum

Answer

Floppy mitral valve

Answer

ASD secundum with rheumatic MR

Cardiology — MCQs

Cardiology — MCQs

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