Cardiology — MCQs

Cardiology Indian Medical PG Practice Questions and MCQs

Question 1421: A 35-year-old woman presents with palpitations and anxiety. An ECG shows a regular, narrow-complex tachycardia at 160 bpm consistent with supraventricular tachycardia. What is the first-line treatment?

A. Adenosine (Correct Answer)
B. Calcium channel blocker
C. Carotid sinus massage
D. Beta-blocker

Explanation: ***Adenosine*** - **Adenosine** is the **first-line pharmacological treatment** for hemodynamically stable patients with **supraventricular tachycardia (SVT)** due to its rapid onset and short half-life. - It works by transiently blocking the **AV node**, interrupting the re-entrant pathway responsible for most SVTs. *Calcium channel blocker* - While **calcium channel blockers** like verapamil or diltiazem can be used for rate control in SVT, they are generally **second-line treatments** after adenosine. - Their slower onset of action and longer duration of effect make them less ideal for immediate termination of acute SVT compared to adenosine. *Carotid sinus massage* - **Carotid sinus massage** is a **vagal maneuver** that can be attempted as a first-line intervention *before* pharmacological therapy in stable SVT. - However, the question asks for **first-line *treatment***, implying a pharmacological approach, and while valuable, vagal maneuvers are often insufficient to terminate SVT compared to adenosine. *Beta-blocker* - **Beta-blockers** can be used as **rate-controlling agents** in SVT and for long-term prevention, but they are not the immediate first-line agent for acute termination in hemodynamically stable patients. - Their onset of action is slower than adenosine, and other agents are often preferred for rapid conversion of SVT.

Question 1422: A 70-year-old man presents with new-onset chest pain and ST elevation on ECG. What is the most likely underlying pathology?

A. Atherosclerotic plaque rupture (Correct Answer)
B. Pericarditis
C. Myocarditis
D. Pulmonary embolism

Explanation: ***Atherosclerotic plaque rupture*** - The **ST elevation** on ECG and new-onset chest pain in an older patient suggest an acute myocardial infarction due to **plaque rupture** [3]. - This is a common cause of myocardial ischemia in the elderly, leading to **coronary artery occlusion** [1]. *Pulmonary embolism* - Typically presents with **dyspnea**, pleuritic chest pain, and may cause ST changes, but often leads to **more diffuse ST elevation** rather than localized elevation. - Lack of signs like **hemoptysis** or signs of right heart strain reduces its likelihood in this context. *Myocarditis* - While it can cause chest pain and ECG changes, it is more often associated with **viral infections** and does not commonly present as ST elevation in isolation. - Myocarditis also typically includes **elevated inflammatory markers** and might show **arrhythmias**, distinguishing it from acute myocardial infarction. *Pericarditis* - Usually characterized by **sharp chest pain** that improves with sitting forward and is often associated with a pericardial rub, not typically causing ST elevation. - ST elevation in pericarditis often shows a more **diffuse pattern** across multiple leads, differing from the localized elevation seen in myocardial infarction [2].

Question 1423: A patient presents with hyperkalemia. Which of the following ECG changes is most likely to be observed?

A. Prolonged QT interval
B. Peaked T waves (Correct Answer)
C. Flattened P waves
D. ST depression

Explanation: ***Peaked T waves*** - **Peaked T waves** are an early and characteristic sign of hyperkalemia, due to altered **myocardial repolarization** [1]. - This ECG change becomes apparent even with moderately elevated potassium levels, often preceding other more severe manifestations [1]. *Prolonged QT interval* - A **prolonged QT interval** is associated with conditions like **hypocalcemia** and certain antiarrhythmic medications, not hyperkalemia. - Hyperkalemia tends to shorten the QT interval indirectly due to the effect on repolarization and QRS widening. *Flattened P waves* - **Flattened P waves** can occur in hyperkalemia, but they typically manifest at higher potassium levels (severe hyperkalemia) and are not the *most likely* initial or sole ECG change [1], [2]. - Other conditions like **hypokalemia** can also cause flattened or inverted T waves. *ST depression* - **ST depression** often indicates **myocardial ischemia** or certain drug toxicities (e.g., digoxin). - It is not a typical or primary ECG finding associated with hyperkalemia.

Question 1424: In a patient with acute chest pain and elevated troponin, which of the following findings would most strongly suggest a diagnosis of myocardial infarction?

A. Symmetrical T-wave inversions in V1-V4
B. ST-segment elevation in leads II, III, and aVF (Correct Answer)
C. ST-segment depression in leads V1-V3
D. PR-segment depression in the limb leads

Explanation: **ST-segment elevation in leads II, III, and aVF** - **ST-segment elevation** in contiguous leads is the hallmark of an **acute ST-elevation myocardial infarction (STEMI)**, indicating a **transmural injury** due to complete coronary artery occlusion [1], [2]. - Leads II, III, and aVF correspond to the **inferior wall** of the left ventricle, supplied by the **right coronary artery (RCA)** or, less commonly, the left circumflex artery [1]. *Symmetrical T-wave inversions in V1-V4* - **Symmetrical T-wave inversions** in precordial leads (V1-V4) are often seen in conditions like **ischemia**, **pulmonary embolism**, or **wellens' syndrome** (critical LAD stenosis), but not typically as the primary finding for acute MI [2]. - These findings indicate **myocardial ischemia** but not directly **infarction** in the same way as ST-elevation [2]. *ST-segment depression in leads V1-V3* - **ST-segment depression** in leads V1-V3 is often indicative of **posterior wall myocardial infarction**, but it is a reciprocal change and typically occurs in conjunction with ST-elevation in other leads (e.g., in posterior leads V7-V9) [2]. - While indicative of ischemia, it is not as strong a direct marker of acute infarction as ST-segment elevation [2]. *PR-segment depression in the limb leads* - **PR-segment depression** is a characteristic finding in **pericarditis**, due to inflammation of the atria, rather than myocardial infarction. - It is not an indicator of myocardial ischemia or infarction.

Question 1425: What is a major sign of rheumatic fever?

A. Joint pain (Correct Answer)
B. Fever
C. Skin rash
D. Myocarditis

Explanation: ***Joint pain*** - **Arthritis**, particularly **migratory polyarthritis** affecting large joints, is a common and major manifestation of **rheumatic fever**, often presenting with significant pain and inflammation. - The joint pain is typically acute, affects multiple joints sequentially, and responds well to anti-inflammatory medications. *Fever* - While **fever** is a common symptom of illness and can accompany **rheumatic fever**, it is a non-specific sign and not considered one of the **major diagnostic criteria** (Jones Criteria). - Many conditions can cause fever, making it less distinctive for specifically diagnosing rheumatic fever compared to more characteristic features like arthritis. *Myocarditis* - **Myocarditis** (carditis) is indeed a major manifestation of **rheumatic fever**, indicating inflammation of the heart muscle [1]. - However, the question asks for "a major sign," and while myocarditis is critical, **joint pain** (arthritis) is often the **most common and earliest presenting major symptom** that brings patients to medical attention. *Skin rash* - A characteristic **skin rash**, **erythema marginatum**, is one of the less common but major manifestations of **rheumatic fever**. - However, it is not as frequently observed or as consistently present as **arthritis** in patients with rheumatic fever.

Question 1426: A 60-year-old male with a history of hypertension and diabetes presents with a sudden onset of severe back pain radiating to the abdomen. What is the most likely diagnosis?

A. Acute pancreatitis
B. Aortic dissection (Correct Answer)
C. Renal colic
D. Myocardial infarction

Explanation: ***Aortic dissection*** - Sudden onset of **severe, tearing back pain** radiating to the abdomen is a classic presentation of aortic dissection [1]. - The patient's history of **hypertension** is a significant risk factor for this life-threatening condition [1]. *Acute pancreatitis* - While acute pancreatitis can cause **severe back pain** and abdominal pain, it is typically associated with **epigastric tenderness**, nausea, and vomiting [2]. - The pain is usually described as **boring** and often relieved by leaning forward, unlike the tearing pain described here [2]. *Renal colic* - **Renal colic** presents with severe, colicky flank pain that may radiate to the groin, but it is typically not described as "tearing back pain radiating to the abdomen." - This condition is often associated with **hematuria** and symptoms of urinary tract obstruction. *Myocardial infarction* - Myocardial infarction typically causes **chest pain** that may radiate to the left arm, jaw, or back, but it is rarely described as primary severe back pain radiating to the abdomen. - While patients with diabetes may have atypical presentations, the sudden onset of **tearing pain** is more indicative of an aortic event.

Question 1427: A 65-year-old male with heart failure presents with dyspnea, fatigue, edema, and reduced ejection fraction. Which specific cardiovascular and renal factors contribute to his fluid retention and symptoms?

A. Decreased cardiac output and aldosterone-mediated sodium retention (Correct Answer)
B. Increased systemic vascular resistance and renal vasodilation
C. Enhanced diuresis and decreased cardiac preload
D. Reduced sympathetic tone and increased renal blood flow

Explanation: **Decreased cardiac output and aldosterone-mediated sodium retention** - In heart failure, **decreased cardiac output** leads to reduced renal perfusion, activating the **renin-angiotensin-aldosterone system (RAAS)** [1]. - **Aldosterone** specifically promotes renal retention of sodium and water, directly contributing to **fluid overload**, edema, and worsening dyspnea [1]. *Increased systemic vascular resistance and renal vasodilation* - While **increased systemic vascular resistance** is a feature of heart failure due to compensatory vasoconstriction, **renal vasodilation** is not [1]. - Instead, renal vasoconstriction often occurs to maintain blood pressure, further impairing renal function and promoting fluid retention [1]. *Enhanced diuresis and decreased cardiac preload* - In heart failure, the body experiences **fluid retention** and **increased cardiac preload**, directly contradicting "enhanced diuresis" and "decreased cardiac preload" [1]. - The goal of treatment for heart failure is often to achieve diuresis and reduce preload to alleviate symptoms [3]. *Reduced sympathetic tone and increased renal blood flow* - Heart failure is characterized by an **increased sympathetic tone** as a compensatory mechanism, leading to vasoconstriction and increased heart rate [1]. - **Renal blood flow** is typically *reduced* in heart failure due to compromised cardiac output and sympathetic activation, exacerbating fluid retention [2].

Question 1428: A 65-year-old male with a history of hypertension and diabetes presents with new-onset heart failure symptoms. His ECG shows an atrial rate of 300 bpm and a ventricular rate of 150 bpm. What is the most appropriate treatment?

A. Electrical cardioversion (Correct Answer)
B. Beta-blockers
C. Calcium channel blockers
D. Amiodarone

Explanation: ### Electrical cardioversion - The patient presents with **new-onset heart failure symptoms** in the context of a rapid, irregularly irregular rhythm (implied by atrial rate of 300 bpm and ventricular rate of 150 bpm, suggesting **atrial fibrillation with rapid ventricular response**). [1] - Urgent **electrical cardioversion** is indicated for symptomatic atrial fibrillation, especially with signs of **hemodynamic instability** such as acute heart failure, to restore sinus rhythm promptly. [1] ### Beta-blockers - While beta-blockers are used for **rate control** in atrial fibrillation, they may worsen **acute decompensated heart failure** due to their negative inotropic effects. [1] - They are not the most appropriate initial treatment in a patient with new-onset heart failure symptoms and rapid ventricular response for rhythm conversion. [1] ### Calcium channel blockers - **Non-dihydropyridine calcium channel blockers** (e.g., diltiazem, verapamil) are used for rate control in atrial fibrillation but are **contraindicated** in patients with **heart failure with reduced ejection fraction** due to their negative inotropic effects. [1] - Their use could further compromise cardiac function in this patient presenting with new-onset heart failure. ### Amiodarone - **Amiodarone** is an antiarrhythmic drug used for rhythm control in atrial fibrillation, particularly in patients with structural heart disease or heart failure, and can be used for both acute and chronic management. - However, in the setting of acute symptomatic decompensated heart failure requiring urgent rhythm restoration, **electrical cardioversion** is generally preferred over pharmacological cardioversion with amiodarone for its rapid and more predictable effect.

Question 1429: Which complication is most commonly associated with untreated varicose veins?

A. Venous ulcers (Correct Answer)
B. Pulmonary embolism
C. Arterial thrombosis
D. Deep vein thrombosis

Explanation: ***Venous ulcers*** - Chronic **venous insufficiency** due to varicose veins leads to increased pressure in superficial veins, causing fluid leakage and skin changes [1]. - This persistent inflammation and impaired tissue perfusion eventually result in **skin breakdown** and the formation of painful, slow-healing ulcers, primarily around the ankles [1]. *Pulmonary embolism* - While **deep vein thrombosis (DVT)** can lead to pulmonary embolism, varicose veins themselves are primarily a superficial venous issue and are not a direct or common cause of PE [2]. - PE is a more serious complication typically arising from a clot in the **deep venous system** dislodging and traveling to the lungs [2]. *Arterial thrombosis* - **Arterial thrombosis** involves clot formation in arteries, usually due to atherosclerosis, and is unrelated to varicose veins, which affect the venous system. - The pathophysiology, risk factors, and clinical manifestations of arterial thrombosis are distinct from venous conditions. *Deep vein thrombosis* - Although more advanced varicose veins may slightly increase the risk of **DVT**, it is not the most common complication and is generally less directly associated than venous ulcers [1]. - DVT primarily affects the deeper veins, whereas varicose veins involve the **superficial venous system**.

Question 1430: A 35-year-old man presents with palpitations, sweating, and anxiety. His ECG shows a regular, narrow QRS complex tachycardia at 180 bpm. Which specific vagal maneuver is the most appropriate to attempt first?

A. Ice water immersion (diving reflex)
B. Synchronized cardioversion
C. Valsalva maneuver (Correct Answer)
D. Carotid sinus massage

Explanation: ***Valsalva maneuver*** - The **Valsalva maneuver** is a simple, non-invasive, and often effective first-line vagal maneuver for terminating **stable narrow QRS complex tachycardias**, such as **supraventricular tachycardia (SVT)** [2]. - It works by increasing intrathoracic pressure, stimulating the **vagus nerve**, and thereby slowing conduction through the **AV node**. *Ice water immersion (diving reflex)* - While effective in some cases, **ice water immersion** or the **diving reflex** can be cumbersome to administer in an emergency setting and is typically considered after less invasive maneuvers. - Its mechanism involves a sudden facial immersion in cold water, stimulating a powerful **vagal response**. *Synchronized cardioversion* - **Synchronized cardioversion** is an electrical procedure used for unstable patients or when vagal maneuvers and pharmacological interventions fail. - This patient is described as having palpitations, sweating, and anxiety, which generally indicates a **stable condition** not immediately requiring electrical cardioversion. *Carotid sinus massage* - **Carotid sinus massage** is a vagal maneuver that can be effective but requires careful execution due to the risk of **cerebrovascular events**, especially in older patients or those with **carotid artery disease** [1]. - It should be performed with caution and is often considered after the Valsalva maneuver.

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Coronary Artery Disease and Angina

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Acute Coronary Syndromes

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Heart Failure

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Cardiac Arrhythmias

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Valvular Heart Diseases

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Cardiomyopathies

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Pericardial Diseases

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Congenital Heart Disease in Adults

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Hypertension and Hypertensive Emergencies

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Pulmonary Hypertension

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Non-invasive Cardiac Diagnostics

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Preventive Cardiology

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Cardiology — MCQs

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