Cardiac Pathology — MCQs

A 45-year-old man receives a cardiac allograft for dilated cardiomyopathy. Five years later, he has worsening exercise tolerance with increasing dyspnea and peripheral edema. Echocardiography shows a reduced ejection fraction of 35%. Which of the following pathologic abnormalities has he most likely developed in the allograft?

Q148Easy

Mitral valve vegetations do not usually embolize to which of the following organs?

Q149Easy

What is the most common site for myocardial infarction?

Q150Easy

To which of the following cell types do 'heart failure' cells belong?

Cardiac Pathology Indian Medical PG Practice Questions and MCQs

Question 141: What is the characteristic position of vegetations on the heart valve in non-bacterial thrombotic endocarditis?

A. Within the valve leaflets
B. On the atrial side of the cusps
C. On the ventricular side of the cusps
D. Along the line of valve closure (Correct Answer)

Explanation: **Non-Bacterial Thrombotic Endocarditis (NBTE)**, also known as marantic endocarditis, is characterized by the formation of small, sterile, friable thrombi (vegetations) composed of fibrin and platelets. **Why the correct answer is right:** The vegetations in NBTE typically occur **along the line of valve closure** [1]. This is because the mechanical stress and minor endothelial trauma at the point where the valve leaflets meet act as a nidus for platelet deposition, especially in patients with hypercoagulable states (e.g., advanced malignancy or systemic inflammation). Unlike infective endocarditis, these vegetations are non-invasive and do not cause significant valve destruction. **Why the incorrect options are wrong:** * **Within the valve leaflets:** Vegetations are surface phenomena (exophytic), not intramural. * **On the atrial side of the cusps:** This is the characteristic location for vegetations in **Infective Endocarditis** (on the "upstream" side of the valves) [1]. * **On the ventricular side of the cusps:** This is also more typical of Infective Endocarditis (on the ventricular side of the aortic valve). **High-Yield Facts for NEET-PG:** * **Association:** Strongly associated with **mucinous adenocarcinomas** (Trousseau sign/migratory thrombophlebitis) and wasting diseases (Marasmus). * **Morphology:** Small (1–5 mm), sterile, bland, and loosely attached [1]. * **Complication:** High risk of **systemic embolization** (e.g., stroke) because they are very friable. * **Comparison:** * **Rheumatic Fever:** Small, firm verrucae along the line of closure [1]. * **Libman-Sacks (SLE):** Small vegetations on **both sides** of the valve leaflets (undersurface and chordae) [1]. * **Infective Endocarditis:** Large, bulky, friable, and destructive vegetations [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, p. 568.

Question 142: Anitschow cells are found in all of the following conditions except:

A. Sickle cell anemia
B. Thalassemia (Correct Answer)
C. Aphthous ulcer
D. Rheumatic heart disease

Explanation: ### Explanation **Anitschow cells** (also known as "caterpillar cells") are modified activated macrophages characterized by an elongated nucleus with a central, wavy ribbon of chromatin [1]. While classically associated with **Rheumatic Heart Disease (RHD)**, they are not pathognomonic for it and can be found in various inflammatory and reactive conditions. **1. Why Thalassemia is the Correct Answer:** Anitschow cells are typically found in conditions involving cardiac inflammation or specific mucosal lesions. **Thalassemia** is a genetic hemoglobinopathy characterized by ineffective erythropoiesis and chronic hemolysis [3], [4]. It does not typically feature the specific inflammatory or granulomatous processes that trigger the formation of Anitschow cells [5]. **2. Analysis of Other Options:** * **Rheumatic Heart Disease (RHD):** This is the most common association. Anitschow cells are a hallmark component of the **Aschoff body** (the pathognomonic lesion of RHD) [1]. * **Sickle Cell Anemia:** Interestingly, Anitschow cells have been documented in the hearts of patients with Sickle Cell Anemia, likely due to chronic ischemic injury and reactive changes in the myocardium [2]. * **Aphthous Ulcer:** These cells are frequently found in the base of common mouth ulcers (canker sores). Their presence here is a high-yield fact often used to test the "non-cardiac" locations of Anitschow cells. **Clinical Pearls for NEET-PG:** * **Aschoff Body Evolution:** Anitschow cells (activated macrophages) can fuse to form multinucleated **Aschoff giant cells** [1]. * **Pathognomonic vs. Suggestive:** While Anitschow cells are found in many places, the **Aschoff Body** itself is pathognomonic for Rheumatic Carditis [1]. * **Microscopy:** On longitudinal section, they look like "caterpillars"; on cross-section, they look like "owl eyes" (due to the central chromatin). **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, p. 566. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, pp. 652-654. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 590-591. [4] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Red Blood Cell and Bleeding Disorders, p. 648. [5] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Blood And Bone Marrow Disease, pp. 601-602.

Question 143: A 26-year-old man died while playing. His autopsy of the heart revealed myocyte hypertrophy. What is the most likely diagnosis?

A. Hypertrophic Obstructive Cardiomyopathy (HOCM) (Correct Answer)
B. Dilated Cardiomyopathy (DCM)
C. Arrhythmogenic Cardiomyopathy
D. Restrictive Cardiomyopathy

Explanation: ### Explanation **Correct Option: A. Hypertrophic Obstructive Cardiomyopathy (HOCM)** The clinical presentation of sudden cardiac death (SCD) in a young athlete is the classic "textbook" scenario for HOCM [2]. Pathologically, HOCM is characterized by massive **myocyte hypertrophy**, myofiber disarray, and interstitial fibrosis [1]. The hypertrophy is typically asymmetric, involving the interventricular septum more than the free wall, leading to left ventricular outflow tract (LVOT) obstruction [1]. In NEET-PG, "Sudden death in a young athlete" + "Myocyte hypertrophy" is a high-yield diagnostic triad for HOCM. **Incorrect Options:** * **B. Dilated Cardiomyopathy (DCM):** Characterized by four-chamber dilation and systolic dysfunction [3]. While myocytes may be hypertrophied, the hallmark is **thinning of the ventricular walls** and "flabby" heart, not isolated hypertrophy. * **C. Arrhythmogenic Cardiomyopathy (ARVC):** This also causes SCD in athletes, but the hallmark histological finding is the **replacement of the right ventricular myocardium with fibrofatty tissue**, not primary myocyte hypertrophy [3]. * **D. Restrictive Cardiomyopathy:** Characterized by stiff walls and impaired filling (diastolic dysfunction). It is most commonly associated with infiltrative diseases like **amyloidosis** (Congo red staining) or sarcoidosis, rather than primary myocyte hypertrophy. **High-Yield Clinical Pearls for NEET-PG:** * **Genetics:** Most commonly due to mutations in genes encoding sarcomeric proteins, specifically **Beta-myosin heavy chain** (most common) and **Myosin-binding protein C**. * **Histology:** Look for **"Myofiber Disarray"** (disorganized bundles of myocytes) [1]. * **Murmur:** Harsh systolic ejection murmur that **increases with Valsalva** (decreased preload) and decreases with squatting. * **Gross Pathology:** "Banana-shaped" left ventricular cavity due to septal bulging [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, pp. 577-578. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Cardiovascular Disease, pp. 303-304. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, p. 576.

Question 144: Troponin-T is preferable to CPK-MB in the diagnosis of acute myocardial infarction (MI) in all of the following situations except?

A. Bedside diagnosis of MI
B. Postoperatively (after CABG)
C. Reinfarction after 4 days (Correct Answer)
D. Small infarcts

Explanation: ### Explanation The diagnosis of Acute Myocardial Infarction (MI) relies on the kinetics of cardiac biomarkers. The choice between Troponin-T (cTnT) and CK-MB depends on their duration of elevation in the blood [1]. **1. Why "Reinfarction after 4 days" is the correct answer:** Troponin-T is highly sensitive but remains elevated for **7–14 days** post-MI. If a patient suffers a second heart attack (reinfarction) 4 days after the first, Troponin levels will still be high from the initial event, making it impossible to distinguish a new insult. In contrast, **CK-MB** returns to baseline within **48–72 hours** [1]. Therefore, if CK-MB levels rise again after 4 days, it specifically indicates a **new reinfarction**. **2. Analysis of Incorrect Options:** * **Bedside diagnosis of MI:** Rapid bedside Troponin assays (Point-of-Care Testing) are highly sensitive and specific, making them superior to CK-MB for immediate triage. * **Postoperatively (after CABG):** Skeletal muscle injury during surgery can cause a rise in total CK and CK-MB [1]. Cardiac Troponins are more cardio-specific and are less likely to be falsely elevated by non-cardiac muscle trauma. * **Small infarcts:** Troponins are significantly more sensitive than CK-MB. They can detect "micro-infarctions" (minimal myocardial damage) that do not cause a measurable rise in CK-MB. **3. Clinical Pearls for NEET-PG:** * **Earliest Marker:** Myoglobin (rises in 1–3 hours), but it is non-specific. * **Most Specific Marker:** Cardiac Troponin I (cTnI). * **Marker for Reinfarction:** CK-MB is the gold standard. * **Troponin Kinetics:** Rises in 3–12 hours, peaks at 24 hours, and stays elevated for 1–2 weeks (cTnI: 7–10 days; cTnT: 10–14 days). **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 255-256.

Question 145: What factor is responsible for cardiac hypertrophy?

A. ANF
B. TNF alpha
C. c-myc (Correct Answer)
D. TGF beta

Explanation: **Explanation:** Cardiac hypertrophy is the adaptive response of the myocardium to increased mechanical stress (pressure or volume overload). This process is mediated by a complex signaling cascade involving mechanical sensors, growth factors, and vasoactive agents. **Why C is correct:** The molecular basis of cardiac hypertrophy involves the **induction of immediate-early genes**, specifically **c-myc, c-fos, and c-jun** [1]. These transcription factors are activated within minutes of mechanical stress. They trigger a "fetal gene program" that leads to increased protein synthesis, the assembly of new sarcomeres, and the replacement of adult α-myosin heavy chain with the more energy-efficient fetal β-myosin heavy chain [1]. This results in an increase in the size of individual myocytes (hypertrophy) rather than their number [2]. **Analysis of Incorrect Options:** * **A. ANF (Atrial Natriuretic Factor):** While ANF is upregulated during hypertrophy (as part of the fetal gene program), its primary role is to promote salt and water excretion to *reduce* blood volume and pressure. It is a marker of hypertrophy, not the primary driver. * **B. TNF-alpha:** This is a pro-inflammatory cytokine. While it may play a role in the progression to heart failure and cardiac cachexia, it is not the primary factor responsible for the hypertrophic response. * **D. TGF-beta:** This growth factor is primarily associated with **cardiac fibrosis** (replacement of myocytes with collagen) rather than the hypertrophy of the myocytes themselves. **NEET-PG High-Yield Pearls:** * **Hypertrophy vs. Hyperplasia:** Permanent cells like cardiac myocytes and skeletal muscle undergo *only* hypertrophy [2]. * **Gene Expression:** The transition from adult to fetal isoforms (e.g., β-MHC) is a hallmark of pathological hypertrophy [1][2]. * **Morphology:** Pressure overload (e.g., Hypertension) causes **concentric** hypertrophy; Volume overload (e.g., Valvular regurgitation) causes **eccentric** hypertrophy (dilation). **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Cellular Responses to Stress and Toxic Insults: Adaptation, Injury, and Death, pp. 45-46. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Cellular Responses to Stress and Toxic Insults: Adaptation, Injury, and Death, pp. 46-47.

Question 146: What is the diagnostic feature of Rheumatic Heart Disease (RHD)?

A. McCallam patch
B. Aschoff nodules (Correct Answer)
C. Shaggy vegetations
D. Bread and butter pericarditis

Explanation: **Explanation:** **1. Why Aschoff Nodules are the Correct Answer:** Aschoff nodules are the **pathognomonic** (diagnostic) hallmark of Acute Rheumatic Fever [1]. These are small, focal areas of tissue destruction (fibrinoid necrosis) surrounded by immune cells. They represent a delayed hypersensitivity reaction to Group A Beta-hemolytic Streptococci. Microscopically, they contain **Anitschkow cells** (caterpillar cells)—specialized macrophages with wavy chromatin—and multinucleated **Aschoff giant cells** [1]. **2. Why Other Options are Incorrect:** * **McCallum Patch (Option A):** While associated with RHD, it is a feature of chronic disease. It is a subendocardial thickening, usually found in the **posterior wall of the left atrium**, caused by the jet effect of mitral regurgitation. It is not as diagnostic as the Aschoff nodule. * **Shaggy Vegetations (Option C):** This term typically refers to the large, friable vegetations seen in **Infective Endocarditis**. In contrast, RHD presents with small, firm, "wart-like" vegetations called **verrucae** along the lines of valve closure [2]. * **Bread and Butter Pericarditis (Option D):** This describes **fibrinous pericarditis**. While it occurs in the "pancarditis" of RHD, it is non-specific and can also be seen in Uremia, Post-MI (Dressler Syndrome), and Systemic Lupus Erythematosus (SLE). **Clinical Pearls for NEET-PG:** * **Pancarditis:** RHD affects all three layers (Endo-, Myo-, and Pericardium). * **Most Common Valve Affected:** Mitral valve (isolated), followed by Mitral + Aortic [1]. * **Fish-mouth/Button-hole Stenosis:** Characteristic appearance of chronic mitral stenosis in RHD due to commissural fusion [1]. * **Jones Criteria:** Used for clinical diagnosis (Major: Joint, Carditis, Nodules, Erythema marginatum, Sydenham chorea). **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, pp. 566-567. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, p. 568.

Question 147: A 45-year-old man receives a cardiac allograft for dilated cardiomyopathy. Five years later, he has worsening exercise tolerance with increasing dyspnea and peripheral edema. Echocardiography shows a reduced ejection fraction of 35%. Which of the following pathologic abnormalities has he most likely developed in the allograft?

A. Amyloidosis
B. Constrictive pericarditis
C. Coronary arteriopathy (Correct Answer)
D. Non-Hodgkin lymphoma

Explanation: The patient is presenting with late-stage heart failure (reduced ejection fraction, dyspnea, edema) five years after a cardiac transplant. This clinical picture is classic for **Chronic Allograft Rejection**. **Why Coronary Arteriopathy is correct:** The hallmark of chronic cardiac transplant rejection is **Graft Vascular Disease (GVD)**, also known as **accelerated graft coronary arteriopathy**. Unlike typical atherosclerosis, which is eccentric and focal, this condition is characterized by **concentric, diffuse intimal hyperplasia** of the coronary arteries. This leads to progressive luminal narrowing, silent myocardial ischemia (due to the denervated heart), and eventual ischemic cardiomyopathy [1] with systolic dysfunction. It remains the most significant long-term limitation to cardiac transplantation survival. **Why the other options are incorrect:** * **A. Amyloidosis:** While systemic amyloidosis can cause restrictive cardiomyopathy [2], it is not a standard complication of cardiac transplantation. * **B. Constrictive pericarditis:** This involves fibrosis of the pericardium. While it can occur post-surgery, it typically presents with signs of diastolic dysfunction rather than a primary drop in ejection fraction (systolic failure). * **D. Non-Hodgkin lymphoma:** Post-Transplant Lymphoproliferative Disorder (PTLD), often EBV-associated, is a risk due to immunosuppression, but it usually presents as a mass lesion or systemic illness rather than progressive heart failure. **Clinical Pearls for NEET-PG:** * **Hyperacute Rejection:** Minutes to hours; Type II Hypersensitivity (Pre-formed antibodies); Fibrinoid necrosis. * **Acute Cellular Rejection:** Weeks to months; Type IV Hypersensitivity (T-cells); Endomyocardial biopsy shows **interstitial lymphocytic infiltrates** with myocyte damage. * **Chronic Rejection:** Years; characterized by **vascular intimal proliferation** (Coronary Arteriopathy). * **Key Fact:** Because the transplanted heart is denervated, patients do not experience classic angina; they present directly with CHF or sudden death. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, p. 558. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, p. 580.

Question 148: Mitral valve vegetations do not usually embolize to which of the following organs?

A. Brain
B. Liver
C. Spleen
D. Lung (Correct Answer)

Explanation: **Explanation:** The correct answer is **Lung (Option D)**. This question tests your understanding of the circulatory pathway and the destination of systemic versus pulmonic emboli. **1. Why "Lung" is the correct answer:** The mitral valve is located on the **left side** of the heart (between the left atrium and left ventricle). When vegetations (seen in Infective Endocarditis or Marantic Endocarditis) break off from the mitral valve, they enter the **systemic circulation** via the aorta [1]. These emboli travel through the arterial tree to various organs [2]. For an embolus to reach the lungs, it must originate from the **right side** of the heart (Tricuspid or Pulmonary valves) or the venous system (e.g., DVT) [5], as it would travel through the vena cava into the right atrium, right ventricle, and finally the pulmonary artery. **2. Why the other options are incorrect:** * **Brain (A):** The carotid arteries are major branches of the aortic arch. Mitral vegetations frequently embolize here, leading to ischemic strokes or mycotic aneurysms [4]. * **Spleen (C) and Liver (B):** These are major abdominal organs supplied by branches of the abdominal aorta (Celiac trunk). Splenic infarction is a common clinical manifestation of systemic embolization from the left heart [2]. **Clinical Pearls for NEET-PG:** * **Right-sided Endocarditis:** Most commonly involves the **Tricuspid valve** and is classically seen in **IV drug users** (*S. aureus*). These patients present with **pulmonary** symptoms (septic pulmonary infarcts). * **Left-sided Endocarditis:** Most common overall; involves Mitral or Aortic valves. Leads to **systemic** emboli (Brain, Spleen, Kidneys, Extremities) [2]. * **Paradoxical Embolism:** A rare scenario where a venous embolus reaches the systemic circulation (e.g., brain) by bypassing the lungs through a **Patent Foramen Ovale (PFO)** or ASD [3]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 145-146. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Hemodynamic Disorders, Thromboembolic Disease, and Shock, pp. 136-137. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 144-145. [4] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 146-147. [5] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Respiratory Tract Disease, pp. 323-324.

Question 149: What is the most common site for myocardial infarction?

A. Left atrium
B. Left ventricle (Correct Answer)
C. Right atrium
D. Right ventricle

Explanation: **Explanation:** The **Left Ventricle (LV)** is the most common site for myocardial infarction (MI) because it is the most metabolically active and hemodynamically burdened chamber of the heart. The LV must generate high systemic pressures to pump blood throughout the body, resulting in a thicker muscular wall and higher oxygen demand compared to other chambers [3]. Furthermore, coronary perfusion to the LV occurs primarily during diastole; high intramural pressure during systole makes the subendocardial layer of the LV particularly vulnerable to ischemia [2]. **Analysis of Options:** * **Left Ventricle (Correct):** Nearly all MIs involve the LV. The most common specific site is the **anterior wall**, supplied by the Left Anterior Descending (LAD) artery (the "widow-maker") [1]. * **Right Ventricle (Incorrect):** Isolated RV infarction is rare (2–3%) because the RV has a lower muscle mass, lower oxygen demand, and receives better collateral flow. It usually occurs only as an extension of a posterior or inferior LV infarct. * **Atria (Incorrect):** Atrial infarctions (Right or Left) are clinically uncommon and usually occur in conjunction with ventricular infarcts. The atrial walls are thin and can partially meet their oxygen requirements through direct diffusion from the blood within the chambers. **High-Yield NEET-PG Pearls:** 1. **Frequency of Artery Occlusion:** LAD (40-50%) > RCA (30-40%) > Left Circumflex (15-20%). 2. **LAD Occlusion:** Leads to infarction of the anterior wall of the LV and the anterior 2/3rd of the interventricular septum [1]. 3. **RCA Occlusion:** Leads to infarction of the posterior wall of the LV and the posterior 1/3rd of the septum. 4. **Subendocardium:** This is the "watershed" area and the first region to undergo necrosis during an MI [2]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Cardiovascular Disease, pp. 286-288. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, p. 550. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, p. 536.

Question 150: To which of the following cell types do 'heart failure' cells belong?

A. Myocytes
B. Macrophages (Correct Answer)
C. Adipocytes
D. Pacemaker cells

Explanation: **Explanation:** **Heart failure cells** are **hemosiderin-laden alveolar macrophages** [2]. They are a hallmark finding in the lungs of patients with **chronic passive congestion**, most commonly caused by **Left-Sided Heart Failure**. 1. **Why Macrophages are correct:** In left-sided heart failure, the left ventricle cannot pump blood efficiently, leading to increased pressure in the pulmonary capillaries [1]. This causes red blood cells (RBCs) to leak into the alveolar spaces (micro-hemorrhages). Alveolar macrophages phagocytose these RBCs and break down the hemoglobin into **hemosiderin**, a golden-brown pigment [2]. These pigment-filled macrophages are then termed "heart failure cells." 2. **Why other options are incorrect:** * **Myocytes:** These are muscle cells (cardiac or skeletal). While myocytes undergo hypertrophy or atrophy in heart failure, they do not phagocytose RBCs. * **Adipocytes:** These are fat-storing cells. They are found in the epicardium but do not play a role in the pulmonary response to congestion. * **Pacemaker cells:** These are specialized myocytes (like those in the SA node) responsible for electrical conduction, not phagocytosis. **High-Yield Clinical Pearls for NEET-PG:** * **Staining:** To confirm the presence of hemosiderin in these macrophages, the **Prussian Blue (Perl’s) stain** is used, which stains the iron blue. * **Gross Pathology:** Chronic congestion leads to a firm, reddish-brown lung, a condition known as **"Brown Induration"** of the lungs. * **Nutmeg Liver:** While heart failure cells are seen in the lungs (Left HF), "Nutmeg Liver" (centrilobular congestion) is the characteristic finding in the liver due to **Right-Sided Heart Failure** [2]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, pp. 536-537. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Hemodynamic Disorders, Thromboembolic Disease, and Shock, p. 126.

Practice by Chapter

Congenital Heart Disease

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Ischemic Heart Disease

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Hypertensive Heart Disease

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Valvular Heart Disease

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Myocarditis and Cardiomyopathies

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Pericardial Disease

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Cardiac Tumors

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Heart Failure Pathophysiology

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Cardiac Transplantation Pathology

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Endocarditis

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