Cardiac Pathology Practice Questions

Q: Irreversible changes in myocardial infarction are typically seen after how much time?

20 minutes. **Explanation:** The transition from reversible to irreversible cell injury in myocardial infarction (MI) is a critical time-dependent process. **Why 20 minutes is correct:** When coronary blood flow is obstructed, myocardial cells immediately switch to anaerobic metabolism. However, they can only tolerate severe ischemia for a limited window. **Irreversible injury (necrosis)** typically begins after **20 to 40 minutes** of persistent ischemia [1]. During this period, the sarcolemmal membrane is breached, and intracellular enzymes (like Troponins and CK-MB) begin to leak into the interstitium. This 20-minute mark represents the "point of no return" where cell death (coagulative necrosis) becomes inevitable. **Analysis of Incorrect Options:** * **A. A few seconds:** Within 0–2 minutes, ATP levels drop and contractility ceases (functional failure), but these changes are entirely **reversible** if perfusion is restored [1]. * **B. 10 minutes:** At this stage, the myocardium remains in a state of reversible injury. While ultrastructural changes like mitochondrial swelling occur, the cells are still viable [1]. * **D. 40 minutes:** While necrosis continues to progress at 40 minutes, the *initial* onset of irreversible damage is established by the 20-minute threshold [1]. **High-Yield Clinical Pearls for NEET-PG:** * **First 0–2 minutes:** Loss of contractility (Reversible) [1]. * **20–40 minutes:** Irreversible injury/Necrosis begins [1]. * **2–4 hours:** First time CK-MB/Troponins can be detected in blood. * **4–12 hours:** Earliest light microscopic change (Wavy fibers) [1]. * **Gross Change:** The first visible gross change is **mottling**, seen between 12–24 hours (Triphenyl Tetrazolium Chloride/TTC stain can detect it earlier as a "pale area") [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, pp. 548-556.

Q: A 15-year-old boy presented with pancarditis. A myocardial biopsy showed a specific finding. What is the most likely diagnosis based on this finding?

Aschoff nodule. ***Aschoff nodule*** - **Aschoff nodules** are **pathognomonic** of **rheumatic carditis** and consist of **fibrinoid necrosis** surrounded by **Anitschkow cells** (enlarged macrophages with owl-eye nuclei) and **multinucleated giant cells**. - In a **15-year-old** with **pancarditis**, finding Aschoff nodules confirms **rheumatic fever**, which commonly affects children and young adults following **Group A Streptococcal** infection. *Tuberculosis* - **TB granulomas** are characterized by **caseating necrosis** with **Langhans giant cells** and **epithelioid cells**, not fibrinoid necrosis. - While TB can cause **pericarditis**, it rarely presents as **pancarditis** in young patients and has different histological features. *Foreign body giant cells* - **Foreign body giant cells** form in response to **inert foreign material** and lack **fibrinoid necrosis** or **Anitschkow cells**. - These are not associated with **pancarditis** and would require a history of **foreign body exposure** or **surgical intervention**. *None of the above* - The presence of **Aschoff nodules** is **diagnostic** of **rheumatic carditis** and is not seen in other cardiac conditions. - Given the **age**, **pancarditis presentation**, and **specific histological finding**, rheumatic fever is the most appropriate diagnosis.

Question 1

What is the characteristic pathological finding in carcinoid heart disease?

Accepted Answer

Fibrous endocardial thickening of the right ventricle, tricuspid valve, and pulmonary valve

Answer

Endocardial thickening of the tricuspid valve with severe tricuspid stenosis

Answer

Collagen-rich, elastic deposits in the endocardium of the right ventricle and pulmonary valve

Answer

Calcification of the tricuspid and pulmonary valves

Question 2

Concentric hypertrophy of the left ventricle is seen in which of the following conditions?

Accepted Answer

Hypertension

Answer

Mitral stenosis

Answer

Aortic regurgitation

Answer

None of the above

Question 3

All are true about hyperopic obstructive cardiomyopathy except?

Accepted Answer

Dilatation of ventricles

Answer

Asymmetric septal hypertrophy

Answer

Dilatation of atria

Answer

Outflow obstruction

Question 4

What is the most common site of myocardial infarction?

Accepted Answer

Anterior wall of the left ventricle

Answer

Posterior wall of the right ventricle

Answer

Posterior wall of the left ventricle

Answer

Inferior wall of the left ventricle

Question 5

Irreversible changes in myocardial infarction are typically seen after how much time?

Accepted Answer

20 minutes

Answer

A few seconds

Answer

10 minutes

Answer

40 minutes

Question 6

What is the most likely diagnosis in a patient presenting with large, friable, irregular vegetations on the heart valves?

Accepted Answer

Infective Endocarditis

Answer

Rheumatic Heart Disease

Answer

Libman-Sacks Endocarditis

Answer

Non-bacterial thrombotic endocarditis

Question 7

Early granulation tissue in acute myocardial infarction is typically seen within which timeframe?

Accepted Answer

1 week

Answer

1 hour

Answer

24 hours

Answer

1 month

Question 8

Myxoma commonly arises from which chamber of the heart?

Accepted Answer

Left atrium

Answer

Left ventricle

Answer

Right ventricle

Answer

Right atrium

Question 9

A 15-year-old boy presented with pancarditis. A myocardial biopsy showed a specific finding. What is the most likely diagnosis based on this finding?

Accepted Answer

Aschoff nodule

Answer

Tuberculosis

Answer

Foreign body giant cells

Answer

None of the above

Question 10

Vegetations on the undersurface of Aortic and Mitral (A.V.) valves are found in which condition?

Accepted Answer

Libman-Sacks endocarditis

Answer

Acute rheumatic fever

Answer

Non-bacterial thrombotic endocarditis

Answer

Chronic rheumatic carditis

Cardiac Pathology — MCQs

Cardiac Pathology — MCQs

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