Cardiology — MCQs

Cardiology Indian Medical PG Practice Questions and MCQs

Question 281: What percentage of critical narrowing of coronary blood vessels is generally considered significant?

A. 70% (Correct Answer)
B. 60%
C. 80%
D. 90%

Explanation: In clinical cardiology, the significance of coronary artery stenosis is defined by its impact on blood flow and oxygen delivery to the myocardium. **1. Why 70% is Correct:** A coronary artery narrowing is generally considered **"critically significant"** when the luminal diameter is reduced by **70% or more**. At this threshold, the vessel's ability to increase blood flow during periods of increased myocardial oxygen demand (exercise or stress) is severely compromised, leading to **exertional angina**. While resting flow is usually maintained until the stenosis reaches approximately 90%, the "70% rule" is the standard threshold for defining obstructive Coronary Artery Disease (CAD) and considering revascularization (PCI or CABG) [1]. **2. Analysis of Incorrect Options:** * **60% (Option B):** While a 50–60% stenosis is considered "moderate," it often does not limit flow enough to cause symptoms under normal stress conditions [2]. * **80% & 90% (Options C & D):** These represent severe stenosis [2]. While definitely significant, they are beyond the *initial* threshold of 70% used to define critical narrowing. A 90% stenosis is specifically associated with the loss of resting flow autoregulation, leading to symptoms even at rest [1]. **3. Clinical Pearls for NEET-PG:** * **Left Main Exception:** For the **Left Main Coronary Artery (LMCA)**, a narrowing of **≥50%** is considered clinically significant due to the vast amount of myocardium it supplies. * **Functional Assessment:** If a lesion is borderline (e.g., 50-70%), **Fractional Flow Reserve (FFR)** is used. An **FFR < 0.80** indicates a hemodynamically significant lesion requiring intervention. * **Gold Standard:** Coronary Angiography (CAG) remains the gold standard for anatomical assessment, but FFR is the gold standard for functional assessment.

Question 282: What is the antihypertensive of choice for a patient with hypertension, diabetes mellitus, and proteinuria?

A. Propranolol
B. Clonidine
C. Enalapril
D. Alpha-methyldopa (Correct Answer)

Explanation: ### Explanation The management of hypertension in patients with **Diabetes Mellitus (DM)** and **proteinuria** is a high-yield topic. The primary goal is not just blood pressure control, but also **renoprotection** [1], [2]. **Why the provided answer (D) is technically controversial but contextually specific:** In modern clinical guidelines (JNC 8, KDIGO), **ACE inhibitors** (like Enalapril) are the absolute first-line agents for DM with proteinuria because they dilate the efferent arteriole, reducing intraglomerular pressure and slowing the progression of diabetic nephropathy [2]. However, in the context of certain traditional examinations or specific patient profiles (such as pregnancy with DM), **Alpha-methyldopa** is highlighted. If this question assumes a **pregnant patient** (a common NEET-PG scenario for Methyldopa), it becomes the drug of choice due to its safety profile. **Analysis of Options:** * **C. Enalapril (ACE Inhibitor):** Under standard non-pregnant conditions, this is the **actual drug of choice**. It reduces proteinuria and provides mortality benefits in diabetic patients [2]. * **A. Propranolol (Beta-blocker):** Generally avoided as first-line in DM because it can mask the tachycardic symptoms of hypoglycemia and may worsen peripheral lipid profiles. * **B. Clonidine (Alpha-2 agonist):** A centrally acting agent used as add-on therapy; it lacks the specific renoprotective benefits required for proteinuric patients. * **D. Alpha-methyldopa:** A centrally acting alpha-2 agonist. While not first-line for general diabetic nephropathy, it is the **gold standard for hypertension in pregnancy**, even if the patient has pre-existing diabetes. **NEET-PG High-Yield Pearls:** 1. **DOC for DM + Proteinuria:** ACE Inhibitors (e.g., Enalapril) or ARBs (e.g., Losartan) [1], [2]. 2. **DOC for HTN in Pregnancy:** Alpha-methyldopa (Labetalol is also frequently used). 3. **Mechanism of ACEi Renoprotection:** Decreased Angiotensin II → Efferent arteriolar vasodilation → Decreased glomerular filtration pressure → Reduced proteinuria [2]. 4. **Side Effect Note:** ACE inhibitors are **contraindicated in pregnancy** (teratogenic) and bilateral renal artery stenosis [1].

Question 283: What constitutes Beck's triad?

A. Increased heart sound, distended neck veins, hypotension
B. Increased heart sound, distended neck veins, hypertension
C. Muffled heart sound, distended neck veins, hypotension (Correct Answer)
D. Muffled heart sound, distended neck veins, hypertension

Explanation: **Explanation:** Beck’s Triad is a classic collection of three clinical signs associated with **Cardiac Tamponade**, a medical emergency where fluid accumulates in the pericardial sac, leading to compression of the heart [1]. **1. Why Option C is correct:** The underlying pathophysiology involves the restriction of cardiac filling and output: * **Hypotension:** Increased intrapericardial pressure limits diastolic filling, leading to decreased stroke volume and reduced cardiac output [1]. * **Distended Neck Veins (Elevated JVP):** The heart cannot expand to receive venous return, causing blood to back up into the superior vena cava and jugular veins. * **Muffled (Distant) Heart Sounds:** The layer of fluid surrounding the heart acts as an acoustic insulator, dampening the sound of the valves closing [1]. **2. Why other options are incorrect:** * **Options A & B:** These suggest "Increased heart sounds." In tamponade, sounds are always muffled or distant due to the fluid barrier [1]. * **Options B & D:** These suggest "Hypertension." Tamponade is characterized by obstructive shock; therefore, blood pressure drops (hypotension) rather than rises. **NEET-PG High-Yield Pearls:** * **Pulsus Paradoxus:** A key finding in tamponade defined as a drop in systolic BP >10 mmHg during inspiration. * **ECG Findings:** Look for **Electrical Alternans** (varying amplitude of QRS complexes) and low-voltage QRS [1]. * **Chest X-ray:** Shows a "Water-bottle" or "Money-bag" shaped heart [1]. * **Definitive Treatment:** Emergency **Pericardiocentesis** [1]. * **Note:** Beck's Triad is present in only about 10-40% of acute tamponade cases, but it remains a high-yield "classic" exam topic.

Question 284: Pulsus paradoxus is present in all of the following conditions EXCEPT:

A. Emphysema
B. Pulmonary embolism
C. Hypovolemic shock
D. Hypertrophic cardiomyopathy (Correct Answer)

Explanation: **Explanation:** **Pulsus paradoxus** is defined as an exaggerated decrease in systolic blood pressure (>10 mmHg) during inspiration. Under normal physiological conditions, inspiration increases venous return to the right heart, causing the interventricular septum to bulge slightly into the left ventricle (LV). In conditions where the heart is compressed or the lungs are hyperinflated, this septal shift significantly compromises LV filling, leading to a drop in stroke volume. **Why Hypertrophic Cardiomyopathy (HCM) is the correct answer:** In **Hypertrophic Cardiomyopathy**, particularly the obstructive type (HOCM), the pathophysiology involves a dynamic outflow tract obstruction and a stiff, non-compliant ventricle. It does not typically involve the exaggerated interventricular dependence seen in pulsus paradoxus. In fact, HCM is classically associated with a **pulsus bisferiens**. **Analysis of Incorrect Options:** * **Emphysema (COPD/Asthma):** These conditions cause hyperinflation of the lungs. Large swings in intrathoracic pressure during labored breathing increase the pooling of blood in pulmonary vasculature and impede LV ejection, making pulsus paradoxus a common finding. * **Pulmonary Embolism:** Massive PE leads to acute right ventricular (RV) dilatation. This causes the septum to shift toward the left, restricting LV filling (the "Bernheim effect"), thereby inducing pulsus paradoxus. * **Hypovolemic Shock:** Reduced intravascular volume makes the LV highly sensitive to the minor pressure changes and septal shifts that occur during inspiration, potentially resulting in a paradoxical pulse [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Most Common Cause:** Cardiac Tamponade (Classic "Beck’s Triad") [2]. * **Kussmaul’s Sign vs. Pulsus Paradoxus:** Kussmaul’s sign (rise in JVP on inspiration) is seen in Constrictive Pericarditis, whereas Pulsus Paradoxus is the hallmark of Cardiac Tamponade [2]. * **Reverse Pulsus Paradoxus:** Seen in Hypertrophic Obstructive Cardiomyopathy (HOCM) during positive pressure ventilation. * **Condition with Tamponade but NO Pulsus Paradoxus:** Aortic Regurgitation or ASD (where LV filling is maintained through other mechanisms).

Question 285: A 45-year-old man presents with exertional dyspnea and pitting pedal edema. His neck veins are dilated. A diagnosis of superior vena cava (SVC) syndrome is made. What is the next diagnostic step?

A. Perform a total blood count and peripheral smear
B. Perform a CT scan of the chest (Correct Answer)
C. Initiate cyclophosphamide therapy
D. Initiate radiotherapy

Explanation: Superior Vena Cava (SVC) syndrome is a clinical emergency caused by the obstruction of blood flow through the SVC, most commonly due to extrinsic compression by a mediastinal mass. In adults, approximately **60–90% of cases are caused by malignancies**, with Bronchogenic Carcinoma (especially Small Cell Lung Cancer) being the most frequent, followed by Lymphoma. **1. Why Option B is correct:** Once SVC syndrome is clinically suspected (dilated neck veins, facial puffiness, dyspnea), the immediate priority is to **confirm the diagnosis and identify the cause**. A **Contrast-Enhanced CT (CECT) scan of the chest** is the gold standard initial diagnostic step [1]. It provides detailed information regarding the site and severity of obstruction, identifies the underlying mass, and helps plan further interventions like biopsy or stenting [1]. **2. Why other options are incorrect:** * **Option A:** While a blood count may show leukocytosis or abnormal cells in leukemia, it is non-specific and does not provide anatomical information about the obstruction. * **Options C & D:** These are therapeutic interventions. Treatment (Chemotherapy or Radiotherapy) should **never** be initiated before establishing a tissue diagnosis (biopsy), unless there is life-threatening airway obstruction or cerebral edema. **Clinical Pearls for NEET-PG:** * **Most common cause:** Bronchogenic Carcinoma. * **Most common benign cause:** Retrosternal Goiter (historically Syphilitic Aneurysm) [1]. * **Pemberton’s Sign:** Facial flushing and inspiratory stridor upon raising both arms; indicates a retrosternal mass compressing the SVC. * **Management:** Elevate the head of the bed, oxygen, and diuretics for symptomatic relief while awaiting definitive diagnosis via CT-guided or bronchoscopic biopsy.

Question 286: Atrial myxoma is associated with which of the following clinical manifestations, except?

A. Fever
B. Weight loss
C. Systolic murmur at apex (Correct Answer)
D. Subungual splinter haemorrhage

Explanation: Atrial myxoma is the most common primary cardiac tumor, typically located in the left atrium (75%). It presents with a classic triad of **constitutional symptoms**, **embolic phenomena**, and **obstructive features**. **Why "Systolic murmur at apex" is the correct (except) answer:** Left atrial myxomas typically mimic **Mitral Stenosis**, not mitral regurgitation. As the tumor prolapses into the mitral orifice during diastole, it causes an obstruction to blood flow, resulting in a **Mid-Diastolic Murmur** [1]. A characteristic "tumor plop" (a low-pitched sound heard shortly after S2) is often present. A systolic murmur would suggest mitral regurgitation [2], which is far less common than the obstructive diastolic murmur [3]. **Analysis of other options:** * **Fever & Weight loss (Options A & B):** Myxomas frequently produce **Interleukin-6 (IL-6)**, a pro-inflammatory cytokine. This leads to constitutional "flu-like" symptoms, including fever, weight loss, malaise, and elevated ESR/CRP, often mimicking systemic vasculitis or connective tissue disease. * **Subungual splinter haemorrhage (Option D):** Myxomas are friable. Fragmentation of the tumor or associated surface thrombi can lead to systemic embolization. This can manifest as strokes, peripheral arterial occlusion, or stigmata mimicking infective endocarditis, such as splinter hemorrhages. **High-Yield NEET-PG Pearls:** * **Most common site:** Fossa ovalis in the Left Atrium. * **Diagnosis:** Echocardiography is the gold standard (shows a pedunculated mobile mass). * **Carney Complex:** An autosomal dominant syndrome (PRKAR1A gene) involving atrial myxomas, skin hyperpigmentation (lentigines), and endocrine overactivity. * **Positional Variation:** Symptoms and murmurs may change characteristically with the patient's body position.

Question 287: Which one of the following is indicative of cardiac tamponade?

A. Pulsus paradoxus (Correct Answer)
B. Wide pulse pressure
C. Kussmaul's sign
D. Forceful apical impulse

Explanation: **Explanation:** **Cardiac tamponade** is a clinical syndrome caused by the accumulation of fluid in the pericardial space, leading to increased intrapericardial pressure and impaired diastolic filling of the heart [1]. **1. Why Pulsus Paradoxus is Correct:** Pulsus paradoxus is defined as an exaggerated drop in systolic blood pressure (>10 mmHg) during inspiration. In tamponade, the heart is compressed within a fixed space. During inspiration, increased venous return to the right ventricle causes the interventricular septum to bulge into the left ventricle (ventricular interdependence). This reduces left ventricular stroke volume and systolic pressure, making it a hallmark finding of cardiac tamponade. **2. Why the Other Options are Incorrect:** * **Wide pulse pressure:** Tamponade typically presents with a **narrow pulse pressure** due to reduced stroke volume and compensatory tachycardia [3]. Wide pulse pressure is seen in conditions like Aortic Regurgitation or Patent Ductus Arteriosus [3]. * **Kussmaul’s sign:** This is the paradoxical rise in JVP during inspiration. It is a classic feature of **Constrictive Pericarditis**, not tamponade [2]. In tamponade, the 'y' descent is absent or blunted. * **Forceful apical impulse:** In tamponade, the heart is surrounded by fluid, which insulates the impulse. The apical impulse is typically **faint or impalpable**. **NEET-PG High-Yield Pearls:** * **Beck’s Triad:** Hypotension, Jugular Venous Distension, and Muffled Heart Sounds. * **ECG Findings:** Low voltage QRS and **Electrical Alternans** (pathognomonic) [1]. * **JVP Finding:** Prominent 'x' descent with an **absent 'y' descent**. * **Treatment:** Immediate ultrasound-guided pericardiocentesis [1].

Question 288: Which of the following cardiomyopathies is characterized by a jerky pulse?

A. Dilated cardiomyopathies
B. Hypertrophic cardiomyopathies (Correct Answer)
C. Restrictive cardiomyopathies
D. All of the above

Explanation: **Explanation:** **Hypertrophic Obstructive Cardiomyopathy (HOCM)** is the correct answer because of its unique pathophysiology involving dynamic left ventricular outflow tract (LVOT) obstruction. 1. **Why HOCM is correct:** In HOCM, the pulse is classically described as a **"Jerky Pulse"** (or *Pulsus Bisferiens* in some cases). This occurs because initial ventricular contraction is vigorous, leading to a rapid rise in the arterial pulse [1]. However, as the heart continues to contract, the thickened interventricular septum and the systolic anterior motion (SAM) of the mitral valve cause a sudden obstruction of the LVOT. This results in a mid-systolic dip or "interruption" in flow, followed by a second wave as the ventricle overcomes the pressure, creating the characteristic "jerky" sensation. 2. **Why other options are incorrect:** * **Dilated Cardiomyopathy (DCM):** Characterized by impaired systolic function and low stroke volume. The pulse is typically **small volume (pulsus parvus)** and weak. * **Restrictive Cardiomyopathy (RCM):** Characterized by stiff ventricles and diastolic dysfunction. The pulse volume is usually normal or low, but it is not jerky. It is more commonly associated with elevated JVP and Kussmaul’s sign. **High-Yield Clinical Pearls for NEET-PG:** * **HOCM Pulse:** Also known as a "double-peaked" pulse or *Pulsus Bisferiens* (when associated with AR). * **Triple Ripple:** A palpable third heart sound (S3) or a forceful atrial contraction (S4) combined with a double apical impulse is sometimes seen in HOCM. * **Maneuvers:** The murmur of HOCM **increases** with Valsalva and standing (decreased preload) and **decreases** with squatting or handgrip (increased preload/afterload). This is a frequent NEET-PG favorite.

Question 289: Left axis deviation is seen in all except?

A. Left anterior hemi block
B. Inferior wall MI
C. ASD (Septum secundum) (Correct Answer)
D. Right pneumothorax

Explanation: The standard range for a normal cardiac axis is **-30° to +90°** [1]. Left Axis Deviation (LAD) is defined as an axis more negative than -30° [1]. **Why ASD (Septum Secundum) is the correct answer:** Atrial Septal Defect (ASD) of the **Ostium Secundum** type typically causes volume overload of the right ventricle, leading to **Right Axis Deviation (RAD)** and Right Bundle Branch Block (RBBB). In contrast, ASD **Ostium Primum** is a classic cause of Left Axis Deviation. This distinction is a high-yield "favorite" in postgraduate exams. **Analysis of other options:** * **Left Anterior Hemiblock (LAHB):** This is the most common cause of LAD. Since the anterior fascicle is blocked, depolarization spreads superiorly and to the left, shifting the axis. * **Inferior Wall MI:** Dead myocardial tissue in the inferior wall is electrically silent. The vector of depolarization points away from the infarcted area (upwards), resulting in a "pathological" LAD. * **Right Pneumothorax:** A large pneumothorax can physically shift the mediastinum and the heart toward the left side, resulting in a leftward shift of the QRS axis. **High-Yield Clinical Pearls for NEET-PG:** 1. **LAD Causes:** Left Anterior Hemiblock, LVH (variable), Inferior Wall MI, WPW Syndrome (Right-sided bypass tract), and **ASD Ostium Primum**. 2. **RAD Causes:** Right Ventricular Hypertrophy (RVH), Lateral Wall MI, Pulmonary Embolism, and **ASD Ostium Secundum**. 3. **Mnemonic:** "Primum = Premium (Left/Top)", "Secundum = Second (Right/Bottom)". This helps remember that Primum causes LAD and Secundum causes RAD.

Question 290: The risk of developing infective endocarditis is the least in a patient with?

A. Small VSD
B. Severe aortic regurgitation
C. Severe mitral regurgitation
D. Large ASD (Correct Answer)

Explanation: The risk of **Infective Endocarditis (IE)** is primarily determined by the presence of **high-velocity turbulent blood flow** and a significant pressure gradient between cardiac chambers. Turbulence causes endothelial damage, leading to the deposition of fibrin and platelets (Non-Bacterial Thrombotic Endocarditis), which serves as a nidus for bacterial colonization. **Why Large ASD is the correct answer:** In an Atrial Septal Defect (ASD), the pressure gradient between the left and right atrium is very low [1]. Consequently, the blood flow across the defect is **low-velocity and non-turbulent**. This lack of significant shear stress means the endocardium remains intact, making it the least likely condition among the choices to develop IE. **Analysis of Incorrect Options:** * **Small VSD:** Contrary to intuition, a small VSD carries a **high risk** of IE. The large pressure gradient between the left and right ventricles creates high-velocity "jet" streams that cause significant endothelial trauma. * **Severe Aortic Regurgitation (AR):** Valvular regurgitation creates high-velocity turbulent flow across the valve, making it a high-risk condition for IE. * **Severe Mitral Regurgitation (MR):** Similar to AR, the high pressure difference between the LV and LA during systole creates significant turbulence, predisposing the valve to infection. **High-Yield Clinical Pearls for NEET-PG:** * **Highest Risk Conditions:** Prosthetic heart valves, previous history of IE, and Cyanotic Congenital Heart Diseases (e.g., Tetralogy of Fallot). * **Negligible Risk Conditions:** Secundum ASD, Ischemic Heart Disease (without MR), and MVP without regurgitation [1]. * **Common Site of Vegetation:** In VSD, vegetations usually form on the **right ventricular side** of the defect due to the impact of the high-pressure jet.

Practice by Chapter

Coronary Artery Disease and Angina

Practice Questions

Acute Coronary Syndromes

Practice Questions

Heart Failure

Practice Questions

Cardiac Arrhythmias

Practice Questions

Valvular Heart Diseases

Practice Questions

Cardiomyopathies

Practice Questions

Pericardial Diseases

Practice Questions

Congenital Heart Disease in Adults

Practice Questions

Hypertension and Hypertensive Emergencies

Practice Questions

Pulmonary Hypertension

Practice Questions

Non-invasive Cardiac Diagnostics

Practice Questions

Preventive Cardiology

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free

Cardiology — MCQs

Cardiology — MCQs

On this page

Practice by Chapter

Want unlimited practice?