Cardiology — MCQs

Cardiology Indian Medical PG Practice Questions and MCQs

Question 51: Which of the following conditions exhibits increased murmur intensity upon standing?

A. Aortic stenosis
B. Aortic regurgitation
C. Hypertrophic obstructive cardiomyopathy (Correct Answer)
D. Mitral stenosis

Explanation: ### Explanation The intensity of a cardiac murmur depends on the volume of blood flowing through the valve or the pressure gradient across an obstruction. [2] **1. Why HOCM is Correct:** Hypertrophic Obstructive Cardiomyopathy (HOCM) is unique because its murmur intensity is **inversely proportional** to the volume of the Left Ventricle (LV). When a patient stands, gravity causes venous pooling in the lower limbs, leading to **decreased venous return (preload)**. This reduces the LV end-diastolic volume. A smaller, "emptier" ventricle allows the hypertrophied septum and the mitral valve (SAM - Systolic Anterior Motion) to come closer together, worsening the outflow tract obstruction. [1] Increased obstruction leads to increased turbulence and a **louder murmur**. **2. Analysis of Incorrect Options:** * **Aortic Stenosis (AS):** Standing decreases preload, which reduces the stroke volume passing through the stenotic aortic valve. Less flow equals a **decreased** murmur intensity. [2], [3] * **Aortic Regurgitation (AR) & Mitral Stenosis (MS):** These are diastolic murmurs. Standing reduces the overall blood volume returning to the heart, thereby decreasing the pressure gradients and flow across these valves, leading to **decreased** murmur intensity. [4] **3. High-Yield Clinical Pearls for NEET-PG:** * **The "Rule of Two":** Only two murmurs become **louder** with standing or the Valsalva maneuver (both decrease preload): **HOCM** and **Mitral Valve Prolapse (MVP)**. * **Squatting/Handgrip:** These maneuvers increase preload/afterload and will **decrease** the intensity of HOCM and MVP murmurs while increasing most others (like AS or MR). * **HOCM Murmur:** It is a harsh systolic ejection murmur, best heard at the left sternal border (unlike AS, which radiates to the carotids).

Question 52: Which of the following is the earliest cardiac abnormality to develop in acute rheumatic fever?

A. Mitral regurgitation (MR) (Correct Answer)
B. Mitral stenosis (MS)
C. Aortic regurgitation (AR)
D. Aortic stenosis (AS)

Explanation: **Explanation:** In **Acute Rheumatic Fever (ARF)**, the cardiac involvement (pancarditis) primarily affects the endocardium, leading to valvulitis [2]. The **mitral valve** is the most common valve involved (followed by the aortic valve) [1]. **1. Why Mitral Regurgitation (MR) is correct:** During the acute phase of rheumatic fever, inflammation causes edema and thickening of the valve leaflets and chordae tendineae. This prevents the valve from closing properly during systole, leading to **Mitral Regurgitation** [1]. It is the hallmark clinical finding of acute rheumatic carditis and is often detected as a soft systolic murmur [2]. **2. Why the other options are incorrect:** * **Mitral Stenosis (MS):** This is a **chronic** manifestation of Rheumatic Heart Disease (RHD). It takes years (usually 5–20 years) for repeated inflammation, commissural fusion, and calcification to narrow the valve orifice. It is never seen in the acute phase. * **Aortic Regurgitation (AR):** While AR can occur in acute rheumatic fever, it is less common than MR and usually occurs in association with mitral valve disease, rather than in isolation. * **Aortic Stenosis (AS):** Similar to MS, AS is a chronic sequela resulting from progressive fibrosis and calcification. It is not an acute finding. **Clinical Pearls for NEET-PG:** * **Carey Coombs Murmur:** A short, mid-diastolic murmur heard at the apex in ARF due to active valvulitis (not to be confused with the murmur of MS). * **Order of Valve Involvement:** Mitral > Aortic > Tricuspid > Pulmonary (MATP). * **Aschoff Bodies:** The pathognomonic histological feature of rheumatic carditis. * **Jones Criteria:** Used for diagnosis [2]; Carditis is a major criterion.

Question 53: All of the following are associated with Atrioventricular block, except?

A. Hyperkalemia
B. Hypomagnesemia
C. Hypothyroidism
D. Cushing's syndrome (Correct Answer)

Explanation: **Explanation:** Atrioventricular (AV) block refers to a delay or interruption in the transmission of electrical impulses from the atria to the ventricles [1]. This can be caused by structural damage, autonomic imbalance, or metabolic disturbances. **Why Cushing’s Syndrome is the correct answer:** Cushing’s syndrome is characterized by an excess of glucocorticoids. While it leads to cardiovascular complications like hypertension and metabolic syndrome, it is **not** typically associated with AV conduction delays. In fact, the electrolyte abnormality often seen in Cushing’s is **hypokalemia**, which more commonly predisposes patients to tachyarrhythmias and increased myocardial excitability rather than heart block [2]. **Analysis of Incorrect Options:** * **Hyperkalemia:** Elevated potassium levels decrease the resting membrane potential, leading to slowed conduction through the AV node and His-Purkinje system [2]. It is a classic cause of progressive heart block and sine-wave patterns. * **Hypomagnesemia:** Magnesium is a cofactor for the Na+/K+-ATPase pump. Deficiency can lead to various arrhythmias, including AV blocks and Torsades de Pointes, often by exacerbating other electrolyte imbalances. * **Hypothyroidism:** Myxedema is a well-known cause of reversible AV block. It causes interstitial edema of the conduction system and increased vagal tone, leading to bradycardia and prolonged PR intervals. **High-Yield Clinical Pearls for NEET-PG:** * **Reversible causes of AV block:** Think of the mnemonic **"DIE"**: **D**rugs (Beta-blockers, CCBs, Digoxin), **I**schemia (Inferior wall MI), and **E**lectrolytes (Hyperkalemia) [2]. * **Infectious causes:** Lyme disease and Chagas disease are high-yield associations for heart block. * **Inferior Wall MI:** Frequently involves the RCA, which supplies the AV node in 90% of individuals, leading to transient AV blocks [3].

Question 54: Which of the following are causes of restrictive cardiomyopathy?

A. Amyloidosis, Sarcoidosis, Viral Myopathy (Correct Answer)
B. Sarcoidosis, Viral Myopathy, Alcohol-induced myopathy
C. Viral Myopathy, Alcohol-induced myopathy, Storage diseases
D. Amyloidosis, Viral Myopathy, Alcohol-induced myopathy

Explanation: **Explanation:** Restrictive Cardiomyopathy (RCM) is characterized by rigid ventricular walls that resist diastolic filling, leading to elevated filling pressures despite normal or near-normal systolic function. **1. Why Option A is Correct:** The correct answer includes conditions that cause myocardial infiltration or inflammation leading to fibrosis: * **Amyloidosis:** The most common cause of RCM [2]. Deposition of amyloid proteins in the interstitium causes the myocardium to become stiff and non-compliant [2]. * **Sarcoidosis:** Granulomatous infiltration leads to scarring and restrictive physiology (though it can also present with conduction blocks). * **Viral Myopathy:** While viral infections typically cause Dilated Cardiomyopathy (DCM) [1], the **post-inflammatory fibrotic stage** of viral myocarditis can result in a restrictive pattern. **2. Why Other Options are Incorrect:** * **Alcohol-induced Myopathy:** This is a classic cause of **Dilated Cardiomyopathy (DCM)** [1]. Chronic alcohol consumption exerts a direct toxic effect on myocytes, leading to ventricular enlargement and impaired systolic function (reduced ejection fraction), rather than restriction [2]. * **Storage Diseases:** While some storage diseases (like Hemochromatosis or Fabry disease) can cause RCM [2], the presence of "Alcohol-induced myopathy" in options B, C, and D automatically disqualifies them. **NEET-PG High-Yield Pearls:** * **Amyloidosis:** Look for "Sparkling/Speckled" appearance on Echocardiography and low voltage ECG despite thick walls. * **Endomyocardial Fibrosis (EMF):** A common cause of RCM in tropical regions (like South India), often associated with eosinophilia (Löffler’s endocarditis) [2]. * **Differentiating RCM from Constrictive Pericarditis:** This is a favorite exam topic. RCM usually shows a higher BNP and lacks the "respiratory variation" in ventricular filling seen in pericarditis.

Question 55: What does a tall R wave in the ECG represent?

A. Right atrial overload
B. Left atrial overload
C. Right ventricular hypertrophy (Correct Answer)
D. All of the above

Explanation: ### Explanation **Correct Answer: C. Right ventricular hypertrophy (RVH)** **Underlying Concept:** In a normal ECG, the left ventricle (LV) is much larger than the right ventricle (RV), so the electrical forces are directed toward the left. This results in a small R wave and a deep S wave in lead V1 [1]. In **Right Ventricular Hypertrophy (RVH)**, the increased muscle mass of the RV shifts the electrical vector toward the right and anteriorly. This reversal of the normal R-wave progression leads to a **tall R wave in lead V1** (R/S ratio > 1). **Analysis of Incorrect Options:** * **A & B (Atrial Overload):** Atrial abnormalities are primarily reflected in the **P wave**, not the QRS complex [1]. Right atrial overload (P-pulmonale) presents with tall, peaked P waves (>2.5 mm), while left atrial overload (P-mitrale) presents with broad, notched P waves in lead II or a deep terminal negative deflection in V1. * **D (All of the above):** Since atrial overload does not affect R-wave height, this option is incorrect. **High-Yield Clinical Pearls for NEET-PG:** * **Criteria for RVH:** R wave in V1 > 7 mm, or R/S ratio in V1 > 1, or R in V1 + S in V5/V6 > 10.5 mm. * **Right Axis Deviation:** RVH is almost always accompanied by a rightward shift in the QRS axis (> +90°) [2]. * **Differential Diagnosis for Tall R in V1:** Apart from RVH, consider **Right Bundle Branch Block (RBBB)**, **Posterior Wall MI** (where V1 shows a tall R instead of a Q wave), and **Wolff-Parkinson-White (WPW) Type A**. * **Strain Pattern:** Look for ST-depression and T-wave inversion in V1-V3, indicating RV pressure overload.

Question 56: A 63-year-old woman presents with symptoms of palpitations and atrial flutter on the ECG. Which of the following is the most likely mechanism of this arrhythmia?

A. atrial asystole
B. atrial bigeminy
C. right atrial macro-reentry (Correct Answer)
D. AV nodal reentry

Explanation: **Explanation:** **1. Why Right Atrial Macro-reentry is Correct:** Atrial flutter is classically defined as a **macro-reentrant tachycardia** [1]. In the most common form (Typical Atrial Flutter), the electrical impulse travels in a large circuit around the **right atrium** [3]. This circuit typically involves the **cavotricuspid isthmus (CTI)**—a bridge of tissue between the inferior vena cava and the tricuspid valve—as a critical part of the pathway. This continuous looping results in the characteristic "sawtooth" pattern (F-waves) seen on an ECG, usually at an atrial rate of 250–350 bpm [3]. **2. Why the Other Options are Incorrect:** * **Atrial Asystole (A):** This refers to the absence of electrical and mechanical activity in the atria (flatline), which is the opposite of the rapid, organized activity seen in flutter. * **Atrial Bigeminy (B):** This is a rhythm where every normal sinus beat is followed by a premature atrial contraction (PAC). It is an ectopic phenomenon, not a macro-reentrant circuit. * **AV Nodal Reentry (D):** This is the mechanism for AVNRT (Atrioventricular Nodal Reentrant Tachycardia) [4]. While it is a reentrant rhythm, the circuit is localized within the **AV node** itself, not the atrial myocardium [4]. **3. NEET-PG High-Yield Pearls:** * **Typical Flutter:** Counter-clockwise reentry; shows negative sawtooth waves in leads II, III, and aVF [3]. * **Definitive Treatment:** Radiofrequency catheter ablation of the **cavotricuspid isthmus (CTI)** is the gold standard (high success rate) [2]. * **Drug of Choice for Rate Control:** Beta-blockers or Calcium Channel Blockers (Diltiazem/Verapamil) [2]. * **Anticoagulation:** Patients with atrial flutter require stroke risk assessment (CHA₂DS₂-VASc) similar to atrial fibrillation.

Question 57: Intracavitary electrocardiography is a diagnostic aid in?

A. Tricuspid regurgitation
B. Endocardial fibroelastosis
C. Endomyocardial fibrosis
D. Ebstein's anomaly of the tricuspid valve (Correct Answer)

Explanation: **Ebstein’s Anomaly** is characterized by the downward displacement of the septal and posterior leaflets of the tricuspid valve into the right ventricle. This results in the "atrialization" of the upper portion of the right ventricle. **Why it is the correct answer:** Intracavitary electrocardiography (ECG) is a classic diagnostic tool for Ebstein’s anomaly. When a catheter is passed across the displaced valve: * The **pressure tracing** shows a right ventricular (RV) waveform (high pressure). * The **intracavitary ECG** simultaneously records an atrial-like electrical signal (P-waves) because the electrode is technically in the "atrialized" portion of the ventricle. This dissociation—recording a ventricular pressure pulse alongside an atrial electrical potential—is pathognomonic for Ebstein’s anomaly. **Why other options are incorrect:** * **Tricuspid Regurgitation (A):** Diagnosis is primarily clinical (giant 'v' waves) and confirmed via Echocardiography (Doppler). Intracavitary ECG offers no specific diagnostic benefit here. * **Endocardial Fibroelastosis (B) & Endomyocardial Fibrosis (C):** These are restrictive cardiomyopathies. Diagnosis relies on imaging (MRI/Echo) and endomyocardial biopsy to identify fibrous thickening; intracavitary ECG does not show specific diagnostic patterns for these conditions. **High-Yield Clinical Pearls for NEET-PG:** * **ECG Findings:** "Himalayan" P-waves (tall/peaked), right bundle branch block (RBBB), and a short PR interval if Wolff-Parkinson-White (WPW) syndrome is present (associated in ~20% of cases). * **Auscultation:** Multiple heart sounds (split S1, S2, S3, and S4) creating a "sail sound" or "cadence" rhythm. * **X-ray:** Massive cardiomegaly with a "box-shaped" heart. * **Association:** Maternal intake of **Lithium** during pregnancy.

Question 58: What is the most important investigation for pericardial effusion?

A. Cardiac catheterization
B. Ultrasound (USG)
C. Echocardiography (Correct Answer)
D. X-ray chest

Explanation: **Explanation:** **Echocardiography (Option C)** is the gold standard and most important investigation for pericardial effusion [2]. It is highly sensitive, non-invasive, and can detect as little as 15–20 mL of fluid. Beyond mere detection, it allows for the assessment of the hemodynamic significance of the effusion (e.g., identifying signs of cardiac tamponade like right ventricular diastolic collapse) and helps in quantifying the fluid (small, moderate, or large). **Why other options are incorrect:** * **Cardiac Catheterization (Option A):** While it can show the "square root sign" in constrictive pericarditis or pressure equalization in tamponade, it is invasive and not used for primary diagnosis [1]. * **Ultrasound (Option B):** While echocardiography is technically a specialized form of ultrasound, in clinical exams, "Echocardiography" is the specific and preferred terminology for cardiac imaging. * **X-ray Chest (Option D):** An X-ray only shows an enlarged "water-bottle" or "money-bag" heart silhouette once the effusion exceeds 250 mL [2]. It cannot differentiate between cardiomegaly and effusion. **High-Yield Clinical Pearls for NEET-PG:** * **ECG Findings:** Look for low voltage QRS complexes and **electrical alternans** (pathognomonic for large effusions/tamponade) [2]. * **Beck’s Triad (Tamponade):** Hypotension, JVD, and muffled heart sounds. * **Pulsus Paradoxus:** A drop in systolic BP >10 mmHg during inspiration; a key clinical sign of tamponade. * **Treatment:** Pericardiocentesis is the treatment of choice for symptomatic tamponade, often performed under **echo guidance** for safety [2].

Question 59: Which of the following conditions is a cause of pulsus bisferiens?

A. Left ventricular failure
B. Cardiac tamponade
C. Hypertrophic cardiomyopathy (Correct Answer)
D. Constrictive pericarditis

Explanation: ### Explanation **Pulsus Bisferiens** (or biphasic pulse) is characterized by two strong systolic peaks separated by a mid-systolic dip, felt best in the carotid artery. **Why Hypertrophic Cardiomyopathy (HCM) is correct:** In **Hypertrophic Obstructive Cardiomyopathy (HOCM)**, the first peak represents the rapid initial ejection of blood [4]. This is followed by a sudden mid-systolic obstruction (due to Systolic Anterior Motion of the mitral valve), causing a brief dip in pressure. The second peak occurs as the ventricular pressure rises further to overcome the obstruction and complete the ejection. *Note: Pulsus bisferiens is also classically seen in **Aortic Regurgitation (AR)** or combined **AS + AR**.* **Why the other options are incorrect:** * **A. Left Ventricular Failure:** Characteristically causes **Pulsus Alternans**, where there is a regular rhythm but alternating strong and weak beats due to fluctuating stroke volume [2]. * **B. Cardiac Tamponade:** Classically associated with **Pulsus Paradoxus**, defined as an exaggerated inspiratory drop in systolic blood pressure (>10 mmHg) [3]. * **D. Constrictive Pericarditis:** Also associated with **Pulsus Paradoxus** (in about 1/3 of cases) and Kussmaul’s sign, but not a bisferiens pulse. **High-Yield Clinical Pearls for NEET-PG:** * **Pulsus Bisferiens:** HOCM, AR, and Large PDA. * **Pulsus Parvus et Tardus:** (Slow-rising, low-amplitude pulse) Pathognomonic for **Aortic Stenosis** [4]. * **Dicrotic Pulse:** (Two peaks, one in systole and one in diastole) Seen in low cardiac output states like severe heart failure or sepsis. * **Water-hammer/Corrigan Pulse:** Seen in severe Aortic Regurgitation [1].

Question 60: What medication is indicated for a 62-year-old hypertensive patient with high lipids and atherosclerosis?

A. Low dose aspirin
B. Amlodipine (Correct Answer)
C. Heparin
D. Digoxin

Explanation: ### Explanation **Correct Option: B. Amlodipine** The primary goal in managing a patient with hypertension, dyslipidemia, and atherosclerosis is blood pressure control and cardiovascular risk reduction [3]. **Amlodipine**, a long-acting Dihydropyridine Calcium Channel Blocker (CCB), is a first-line antihypertensive agent [1]. Beyond its potent BP-lowering effects, CCBs like Amlodipine have demonstrated **anti-atherosclerotic properties** by reducing oxidative stress and improving endothelial function [2]. In patients with established atherosclerosis (e.g., Coronary Artery Disease), CCBs are preferred as they provide symptomatic relief for angina while managing hypertension [2]. **Why other options are incorrect:** * **A. Low dose aspirin:** While aspirin is an antiplatelet agent used for secondary prevention of cardiovascular events, it is **not** a treatment for hypertension itself. Current guidelines (USPSTF) have also become more restrictive regarding aspirin for primary prevention due to bleeding risks. * **C. Heparin:** This is an anticoagulant used for acute management of thromboembolic events (like DVT, PE, or NSTEMI). It has no role in the chronic management of hypertension or stable atherosclerosis. * **D. Digoxin:** This is a cardiac glycoside used primarily for rate control in Atrial Fibrillation or as an add-on therapy in symptomatic Heart Failure with Reduced Ejection Fraction (HFrEF). It does not treat hypertension or atherosclerosis. **NEET-PG High-Yield Pearls:** * **First-line HTN drugs:** ACE inhibitors/ARBs, Thiazide diuretics, and CCBs (Amlodipine) [1]. * **Amlodipine Side Effect:** Pedal edema (due to precapillary vasodilation). This can be mitigated by adding an ACE inhibitor. * **Atherosclerosis Management:** The "Statin + ACEi/ARB + Antiplatelet" triad is the cornerstone for secondary prevention. * **Drug of Choice:** For HTN with Benign Prostatic Hyperplasia (BPH), use Prazosin; for HTN in pregnancy, use Labetalol or Methyldopa.

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Cardiology — MCQs

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