Cardiology — MCQs

A 45-year-old woman presents with increasing shortness of breath on exertion and fatigue. Physical examination reveals a loud systolic ejection murmur best heard at the left sternal border, which increases with standing. A double apical impulse is also noted. What is the most likely diagnosis for this patient presenting with a systolic murmur?

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A patient presents with pedal edema and a water-hammer pulse. What is the most likely diagnosis?

Cardiology Indian Medical PG Practice Questions and MCQs

Question 721: Which of the following conditions is associated with peripheral artery disease, coronary heart disease, and stroke?

A. Insulin deficiency (Correct Answer)
B. Hyperestrogenemia
C. Hypothyroidism
D. Hyperprogesteronemia

Explanation: The correct answer is **Insulin deficiency**, which is the hallmark of Diabetes Mellitus (DM). DM is a major systemic metabolic disorder and a potent independent risk factor for **Atherosclerosis**. **1. Why Insulin Deficiency is Correct:** Insulin deficiency (or resistance) leads to chronic hyperglycemia [2], which triggers a cascade of vascular damage: * **Endothelial Dysfunction:** Increased oxidative stress and advanced glycation end-products (AGEs) damage the vessel walls. * **Dyslipidemia:** Insulin deficiency promotes the production of small dense LDL and reduces HDL, accelerating plaque formation [1]. * **Pro-thrombotic State:** It increases platelet aggregation and impairs fibrinolysis. These processes lead to **Macrovascular complications**, which manifest clinically as Peripheral Artery Disease (PAD), Coronary Heart Disease (CHD), and Ischemic Stroke [1]. **2. Why Other Options are Incorrect:** * **Hyperestrogenemia:** Estrogen generally has a protective effect on the cardiovascular system in premenopausal women by improving lipid profiles and promoting vasodilation. * **Hypothyroidism:** While hypothyroidism can cause hypercholesterolemia (increasing CHD risk), it is not as strongly or classically associated with the triad of PAD, CHD, and stroke as insulin deficiency is. * **Hyperprogesteronemia:** Progesterone does not have a primary, direct role in the pathogenesis of systemic atherosclerosis. **Clinical Pearls for NEET-PG:** * **DM is considered a "CHD Equivalent":** A patient with DM but no history of MI has the same cardiovascular risk as a non-diabetic patient who has already had an MI [2]. * **PAD in DM:** Usually involves infra-popliteal (distal) arteries and is often multisegmental. * **Metabolic Syndrome:** Remember the "Deadly Quartet": Upper body obesity, glucose intolerance, hypertriglyceridemia, and hypertension.

Question 722: A new systolic murmur after acute myocardial infarction may be due to all of the following EXCEPT?

A. Complete heart block (Correct Answer)
B. Rupture of interventricular septum
C. Papillary muscle dysfunction
D. Ischemic cardiomyopathy

Explanation: The development of a new systolic murmur following an acute myocardial infarction (MI) typically indicates a mechanical complication or structural change. **Why "Complete Heart Block" is the correct answer:** Complete heart block (CHB) is a conduction abnormality, not a structural or valvular defect [3]. It is characterized by AV dissociation and bradycardia [1]. While it may produce a **variable intensity of the first heart sound (S1)** or occasional "cannon a-waves," it does not inherently produce a systolic murmur. Therefore, it is the exception among the listed options. **Analysis of Incorrect Options:** * **Rupture of Interventricular Septum (VSR):** This usually occurs 3–5 days post-MI. It creates a left-to-right shunt, resulting in a new, harsh **pansystolic murmur** best heard at the left lower sternal border, often accompanied by a palpable thrill. * **Papillary Muscle Dysfunction:** Ischemia or infarction of the papillary muscles (most commonly the posteromedial muscle in inferior MI) leads to acute **Mitral Regurgitation (MR)**. This presents as a soft or loud pansystolic murmur at the apex radiating to the axilla [2]. * **Ischemic Cardiomyopathy:** Chronic ischemia leads to left ventricular (LV) dilatation and remodeling [2]. This "functional" change causes displacement of papillary muscles and annular stretching, resulting in secondary mitral regurgitation and a systolic murmur. **High-Yield Clinical Pearls for NEET-PG:** * **VSR vs. MR:** Both cause a pansystolic murmur. Use a **Swan-Ganz catheter** to differentiate: VSR shows an "oxygen step-up" in the right ventricle, while MR shows large "v-waves" in the PCWP tracing. * **Posteromedial Papillary Muscle:** More prone to rupture because it has a **single blood supply** (RCA), whereas the anterolateral muscle has a dual supply (LAD/LCX). * **Timeframe:** Most mechanical complications (VSR, Papillary rupture, Free wall rupture) occur within the first week (peak 3–5 days) post-MI.

Question 723: Lambert-Eaton myasthenic syndrome is associated with which of the following?

A. Thymoma
B. Small cell lung carcinoma (Correct Answer)
C. Myasthenia gravis
D. Adenocarcinoma of lung

Explanation: **Explanation:** **Lambert-Eaton Myasthenic Syndrome (LEMS)** is a paraneoplastic syndrome caused by autoantibodies directed against **presynaptic P/Q-type voltage-gated calcium channels (VGCC)** at the neuromuscular junction. This leads to impaired release of acetylcholine into the synaptic cleft. 1. **Why Small Cell Lung Carcinoma (SCLC) is correct:** Approximately 50–60% of LEMS cases are associated with an underlying malignancy, and of those, **SCLC** is the most common (found in >90% of paraneoplastic LEMS) [1]. SCLC cells are of neuroendocrine origin and express VGCCs on their surface, which triggers the production of cross-reacting antibodies. [3] 2. **Why other options are incorrect:** * **Thymoma:** Strongly associated with **Myasthenia Gravis (MG)** (found in ~15% of MG patients), but not with LEMS. [4] * **Myasthenia Gravis:** This is a distinct autoimmune disorder caused by antibodies against *postsynaptic* nicotinic acetylcholine receptors. While both cause weakness, their pathophysiology and clinical features differ. [2] * **Adenocarcinoma of lung:** While any malignancy can theoretically trigger paraneoplastic syndromes, SCLC is the classic and most frequent association for LEMS due to its neuroendocrine nature. [1] **NEET-PG High-Yield Pearls:** * **Clinical Triad:** Proximal muscle weakness (starts in lower limbs), autonomic dysfunction (dry mouth, erectile dysfunction), and depressed deep tendon reflexes. * **Lambert’s Sign:** A characteristic finding where muscle strength and reflexes **improve/increase** after repeated muscle contraction or exercise (post-exercise facilitation). This is the opposite of Myasthenia Gravis. * **Diagnosis:** Confirmed by Repetitive Nerve Stimulation (RNS) showing an **incremental response** (increase in CMAP amplitude) at high frequencies. * **Treatment:** 3,4-Diaminopyridine (first-line) and treating the underlying malignancy. [1]

Question 724: A patient presents with ventricular fibrillation, hypotension, and absent peripheral pulses. What is the initial management?

A. Lidocaine push
B. Amiodarone push
C. Atropine push
D. 200 Joule defibrillation (Correct Answer)

Explanation: ### Explanation **Correct Answer: D. 200 Joule defibrillation** **Why it is correct:** The patient is in **Ventricular Fibrillation (VF)**, a "shockable" cardiac arrest rhythm characterized by chaotic electrical activity and no mechanical contraction [1]. In any pulseless cardiac arrest with a shockable rhythm (VF or Pulseless Ventricular Tachycardia), the **most critical intervention is immediate defibrillation** [1]. The goal is to depolarize a critical mass of the myocardium simultaneously, allowing the heart's natural pacemaker (SA node) to resume a normal rhythm [3]. According to ACLS guidelines, for a biphasic defibrillator, the initial energy dose is typically **120–200 Joules**. **Why the other options are incorrect:** * **A & B (Lidocaine/Amiodarone):** These are anti-arrhythmic drugs used in the ACLS algorithm for *refractory* VF (VF that persists after at least 2–3 shocks and CPR). They are never the first-line treatment for VF. * **C (Atropine):** Atropine is used for symptomatic bradycardia or asystole (though no longer routine for the latter). It has no role in the management of VF. **High-Yield Clinical Pearls for NEET-PG:** 1. **Shockable Rhythms:** VF and Pulseless VT [1]. 2. **Non-Shockable Rhythms:** PEA (Pulseless Electrical Activity) and Asystole [1]. These require immediate CPR and Epinephrine, NOT defibrillation. 3. **Time is Myocardium:** For every minute that passes without defibrillation in VF, the probability of survival declines by 7–10% [1]. 4. **Sequence:** Shock → Immediate CPR (2 minutes) → Check Rhythm → Shock (if still VF) → CPR + Epinephrine. Amiodarone is typically given after the 3rd shock [2].

Question 725: A 60-year-old man with a history of left ventricular aneurysm post-myocardial infarction in 2017 presents with recurrent episodes of syncope. Following consumption of coffee, he experienced syncope and was brought to the hospital. What is the best management strategy to prevent future episodes?

A. Daily oral amiodarone
B. Direct current shock at 200 Joules
C. Implantable cardioverter-defibrillator (Correct Answer)
D. Catheter ablation

Explanation: **Explanation:** The patient presents with a history of **Left Ventricular (LV) aneurysm** (a complication of a prior MI) and **syncope**. In the context of structural heart disease, syncope is highly suggestive of **Ventricular Tachycardia (VT)** [2]. An LV aneurysm creates a substrate for re-entrant circuits, making the patient high-risk for Sudden Cardiac Death (SCD) [1]. **Why Option C is Correct:** According to current guidelines, an **Implantable Cardioverter-Defibrillator (ICD)** is the treatment of choice for the **secondary prevention** of SCD in patients with structural heart disease who have experienced life-threatening ventricular arrhythmias or unexplained syncope. The ICD is the only intervention proven to significantly reduce mortality by providing immediate internal defibrillation during a VT/VF episode [5]. **Why Other Options are Incorrect:** * **Option A (Amiodarone):** While amiodarone is a potent anti-arrhythmic, it does not reduce mortality as effectively as an ICD and carries significant long-term toxicity (pulmonary fibrosis, thyroid dysfunction). * **Option B (DC Shock):** This is the treatment for *acute* hemodynamic instability during an active episode of VT/VF. It is not a *preventative* management strategy. * **Option D (Catheter Ablation):** This is typically reserved as an adjunctive therapy for patients with recurrent VT who are already on an ICD or for those who are not candidates for an ICD [3], [4]. It does not replace the need for an ICD in high-risk patients. **High-Yield Clinical Pearls for NEET-PG:** * **LV Aneurysm:** Characterized by persistent ST-segment elevation on ECG months after an MI [1]. * **Most common cause of death post-MI:** Ventricular arrhythmias (VT/VF). * **ICD Indications:** 1. **Secondary Prevention:** Prior VT/VF or syncope with structural heart disease. 2. **Primary Prevention:** LVEF ≤ 35% due to prior MI (at least 40 days post-MI) or non-ischemic cardiomyopathy.

Question 726: Which of the following is NOT included in Acute Coronary Syndrome?

A. STEMI
B. NSTEMI
C. Stable angina (Correct Answer)
D. Unstable angina

Explanation: ### Explanation **Acute Coronary Syndrome (ACS)** is an umbrella term used to describe a range of conditions associated with sudden, reduced blood flow to the heart. The pathophysiology typically involves the **acute rupture or erosion of an atherosclerotic plaque**, leading to varying degrees of coronary artery occlusion and myocardial ischemia. **Why Stable Angina is the Correct Answer:** Stable angina is **not** part of ACS. It is a manifestation of **Chronic Coronary Syndrome**. It occurs due to a fixed, stable atherosclerotic plaque that narrows the coronary artery. Ischemia occurs only when myocardial oxygen demand exceeds supply (e.g., during exertion) and is characteristically relieved by rest or nitroglycerin. There is no acute plaque rupture or thrombus formation involved. **Analysis of Incorrect Options:** * **STEMI (ST-Elevation Myocardial Infarction):** A component of ACS characterized by complete coronary artery occlusion, resulting in transmural necrosis and ST-segment elevation on ECG. * **NSTEMI (Non-ST-Elevation Myocardial Infarction):** A component of ACS where partial occlusion leads to subendocardial necrosis. It is distinguished from unstable angina by the presence of elevated cardiac biomarkers (Troponins). * **Unstable Angina (UA):** A component of ACS characterized by ischemic symptoms at rest or with minimal exertion, but **without** elevation of cardiac biomarkers. **High-Yield Clinical Pearls for NEET-PG:** * **The "Troponin" Rule:** The primary differentiator between Unstable Angina and NSTEMI is the presence of elevated cardiac enzymes (Troponin I or T). * **ECG Findings:** STEMI shows ST-elevation; NSTEMI/UA may show ST-depression, T-wave inversion, or a normal ECG. * **Pathology:** ACS is usually caused by **red or white thrombus** formation, whereas Stable Angina is caused by a **fixed fibrous cap**.

Question 727: Severe hypertension is defined if systolic BP is greater than:

A. 140 mmHg
B. 160 mmHg
C. 180 mmHg (Correct Answer)
D. 200 mmHg

Explanation: **Explanation:** The classification of hypertension is based on the **JNC 8** and **ESC/ESH guidelines**, which categorize blood pressure severity to guide clinical management. **1. Why 180 mmHg is Correct:** According to standard clinical guidelines, **Grade 3 (Severe) Hypertension** is defined as a Systolic Blood Pressure (SBP) **≥180 mmHg** and/or a Diastolic Blood Pressure (DBP) **≥110 mmHg** [1]. At this level, the risk of acute target organ damage (TOD) increases significantly. If this severe elevation is associated with acute TOD (e.g., encephalopathy, MI, or stroke), it is termed a **Hypertensive Emergency**; if no acute TOD is present, it is called **Hypertensive Urgency** [1]. **2. Analysis of Incorrect Options:** * **A. 140 mmHg:** This is the threshold for **Grade 1 (Mild) Hypertension** (SBP 140–159 mmHg). It marks the point where pharmacological intervention is usually initiated if lifestyle modifications fail. * **B. 160 mmHg:** This is the threshold for **Grade 2 (Moderate) Hypertension** (SBP 160–179 mmHg). * **D. 200 mmHg:** While clinically alarming, this is not the formal threshold for the definition of "severe" hypertension in standard classification systems. **High-Yield Clinical Pearls for NEET-PG:** * **Hypertensive Crisis:** SBP >180 or DBP >120 mmHg. * **Management Goal (Emergency):** Reduce Mean Arterial Pressure (MAP) by no more than **25% within the first hour** to prevent cerebral hypoperfusion [1], except in cases of Aortic Dissection or Ischemic Stroke. * **Drug of Choice:** **IV Labetalol** or **Nicardipine** are commonly used; **Sodium Nitroprusside** is reserved for refractory cases due to cyanide toxicity risks [1].

Question 728: In the JVP tracing, which condition is characterized by the absence of 'a' waves?

A. Atrial fibrillation (Correct Answer)
B. Mitral stenosis
C. Tricuspid atresia
D. Myocardial infarction

Explanation: ### Explanation The **'a' wave** in the Jugular Venous Pulse (JVP) represents **right atrial contraction** occurring at the end of diastole. For an 'a' wave to be visible, there must be a coordinated, forceful contraction of the atrial myocardium. **Why Atrial Fibrillation (AF) is correct:** In AF, the organized electrical activity of the atria is replaced by rapid, chaotic fibrillatory waves [1]. This leads to a loss of mechanical atrial contraction (atrial "kick"). Without a coordinated contraction, the 'a' wave disappears from the JVP tracing. **Analysis of Incorrect Options:** * **B. Mitral Stenosis:** Characterized by **prominent (giant) 'a' waves** because the right atrium must contract harder against a non-compliant right ventricle (due to secondary pulmonary hypertension) [2]. * **C. Tricuspid Atresia:** Characterized by **prominent 'a' waves** because the right atrium contracts against a blind/atretic tricuspid valve, often shunting blood through an ASD. * **D. Myocardial Infarction:** While a massive RV infarct can dampen waves, it does not typically cause the complete absence of 'a' waves unless associated with an arrhythmia like AF. **High-Yield Clinical Pearls for NEET-PG:** * **Absent 'a' wave:** Atrial Fibrillation [1]. * **Cannon 'a' waves:** Occur when the atrium contracts against a closed tricuspid valve. Seen in **Complete Heart Block** (irregular), Ventricular Tachycardia, and Junctional Rhythms (regular). * **Giant/Prominent 'a' waves:** Seen in Tricuspid Stenosis, Pulmonary Stenosis, and Right Ventricular Hypertrophy (Pulmonary Hypertension). * **Giant 'cv' waves:** Pathognomonic for **Tricuspid Regurgitation**. * **Steep 'y' descent:** Seen in Constrictive Pericarditis (Friedreich’s sign) and Tricuspid Regurgitation. * **Slow/Absent 'y' descent:** Seen in Cardiac Tamponade and Tricuspid Stenosis.

Question 729: A 45-year-old woman presents with increasing shortness of breath on exertion and fatigue. Physical examination reveals a loud systolic ejection murmur best heard at the left sternal border, which increases with standing. A double apical impulse is also noted. What is the most likely diagnosis for this patient presenting with a systolic murmur?

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

Explanation: ### Explanation **Correct Answer: B. Hypertrophic obstructive cardiomyopathy (HOCM)** The clinical presentation is classic for **HOCM**. The key diagnostic feature here is the **dynamic nature of the murmur**. 1. **Mechanism:** The murmur in HOCM is a systolic ejection murmur caused by left ventricular outflow tract (LVOT) obstruction [1]. 2. **Maneuvers:** Standing reduces venous return (preload), which decreases the left ventricular volume. A smaller ventricle increases the degree of obstruction, thereby **increasing the intensity** of the murmur. 3. **Physical Signs:** The "double apical impulse" (or triple) is due to a forceful atrial contraction against a stiff ventricle (S4) followed by the ventricular lift [1]. **Why Incorrect Options are Wrong:** * **A. Aortic Stenosis (AS):** While AS also presents with a systolic ejection murmur, it is best heard at the right second intercostal space [2]. Crucially, the AS murmur **decreases** with standing (less preload = less flow across the valve). * **C. Mitral Regurgitation (MR):** MR presents with a holosystolic murmur at the apex radiating to the axilla. It generally decreases with standing due to reduced afterload/preload [3]. * **D. Tricuspid Regurgitation (TR):** TR is a holosystolic murmur heard at the lower left sternal border that characteristically increases with **inspiration** (Carvallo’s sign), not standing. **NEET-PG High-Yield Pearls:** * **The "Rule of Two":** Most murmurs decrease with standing/Valsalva (due to less blood in the heart). Only **HOCM** and **Mitral Valve Prolapse (MVP)** increase in intensity with these maneuvers. * **Handgrip Exercise:** Increases afterload; this **decreases** the HOCM murmur but **increases** MR and AR murmurs. * **Drug of Choice:** Beta-blockers (first-line) to improve diastolic filling and reduce the gradient. Avoid Nitrates and Diuretics as they worsen the obstruction.

Question 730: A patient presents with pedal edema and a water-hammer pulse. What is the most likely diagnosis?

A. Thiamine (Vitamin B1) deficiency (Correct Answer)
B. Niacin (Vitamin B3) deficiency
C. Pyridoxine (Vitamin B6) deficiency
D. Cobalamin (Vitamin B12) deficiency

Explanation: The clinical presentation of **pedal edema** (congestive heart failure) combined with a **water-hammer pulse** (bounding pulse due to high cardiac output) is characteristic of **Wet Beriberi**, caused by **Thiamine (Vitamin B1) deficiency** [2]. **1. Why Thiamine (B1) is correct:** Thiamine deficiency manifests in two primary cardiovascular/neurological forms [1]: * **Wet Beriberi:** Leads to peripheral vasodilation, resulting in a high-output heart failure state. This causes increased stroke volume (leading to a **water-hammer pulse**) and sodium/water retention (leading to **pedal edema** and pulmonary congestion) [2]. * **Dry Beriberi:** Presents as symmetrical peripheral neuropathy [2]. * **Wernicke-Korsakoff Syndrome:** CNS involvement (ataxia, ophthalmoplegia, and memory loss) [1]. **2. Why other options are incorrect:** * **Niacin (B3):** Deficiency causes **Pellagra**, characterized by the 3 Ds: Dermatitis (Casal’s necklace), Diarrhea, and Dementia. It does not typically cause high-output heart failure. * **Pyridoxine (B6):** Deficiency leads to sideroblastic anemia, peripheral neuropathy, and seborrheic dermatitis, but not edema or bounding pulses. * **Cobalamin (B12):** Deficiency causes Megaloblastic anemia and Subacute Combined Degeneration (SCD) of the spinal cord. While severe anemia can cause high-output failure, the specific association with Beriberi is more classic for B1. **Clinical Pearls for NEET-PG:** * **High-Output Heart Failure Causes:** Remember the mnemonic **"PAGET"** (Paget’s disease, AV fistulas, Glandular/Thyrotoxicosis, Erythrodermic psoriasis/Severe Anemia, Thiamine deficiency). * **Shoshin Beriberi:** A fulminant form of wet beriberi characterized by rapid-onset cardiovascular collapse and lactic acidosis [2]. * **Treatment:** Always administer Thiamine **before** Glucose in malnourished/alcoholic patients to prevent precipitating Wernicke Encephalopathy.

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Cardiology — MCQs

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