Cardiac Pathology Practice Questions

Q: What is the most common site of myocardial infarction?

Anterior wall of left ventricle. **Explanation:** The location of a myocardial infarction (MI) is determined by the specific coronary artery that is occluded. The **Left Anterior Descending (LAD) artery** is the most frequently involved vessel in coronary atherosclerosis, often referred to as the "widow-maker." 1. **Why Option A is Correct:** The LAD artery supplies the **anterior wall of the left ventricle**, the anterior 2/3rd of the interventricular septum, and the cardiac apex [1]. Because the LAD is the most common site of thrombotic occlusion (40–50% of cases), the **Anterior wall of the left ventricle** is the most common site of infarction [1]. 2. **Why Other Options are Incorrect:** * **Option B & D:** The posterior and inferior walls of the left ventricle are typically supplied by the **Right Coronary Artery (RCA)** [1]. RCA occlusion occurs in approximately 30–40% of cases, making it the second most common site. * **Option C:** Isolated Right Ventricular (RV) infarcts are rare because the RV has a lower oxygen demand and better collateral flow. RV involvement usually occurs as an extension of an inferior wall LV infarct. **NEET-PG High-Yield Pearls:** * **Frequency of Occlusion:** LAD (40-50%) > RCA (30-40%) > Left Circumflex (LCX) (15-20%) [1]. * **LCX Infarction:** Leads to lateral wall ischemia/infarction. * **ECG Correlation:** Anterior wall MI shows ST-elevation in leads **V1–V4**. * **Complication:** Anterior wall infarcts are more likely to lead to free wall rupture, ventricular aneurysms, and cardiogenic shock compared to other sites [2]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, pp. 550-552. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Cardiovascular Disease, pp. 288-289.

Q: All of the following are true regarding marantic endocarditis except?

Affects damaged valves. Explanation: Marantic endocarditis, also known as **Non-Bacterial Thrombotic Endocarditis (NBTE)**, is characterized by the deposition of small, sterile thrombi (fibrin and platelets) on cardiac valves. **Why Option C is the correct answer (The Exception):** Unlike Subacute Bacterial Endocarditis (SBE), which typically occurs on previously damaged or deformed valves, NBTE characteristically occurs on **previously normal valves**. The pathogenesis is not related to structural valve disease or infection, but rather to systemic hypercoagulability or endothelial trauma [1]. **Analysis of other options:** * **Option A:** The vegetations in NBTE are **friable** and loosely attached because there is no significant underlying inflammation or organization. Therefore, they frequently break off and **embolize** to the brain, kidneys, or spleen. * **Option B:** Similar to Rheumatic Heart Disease, the vegetations in NBTE are typically small (1–5 mm) and occur **along the line of closure** of the valve leaflets (most commonly the mitral valve) [1]. * **Option D:** NBTE is strongly associated with **hypercoagulable states**. It is frequently seen in patients with advanced malignancies (especially mucinous adenocarcinomas—known as **Trousseau syndrome**) or profound debilitation (wasting/marasmus) [1]. **High-Yield Clinical Pearls for NEET-PG:** * **Morphology:** Vegetations are sterile, bland, and do not cause significant valvular destruction (unlike Infective Endocarditis) [1]. * **Associations:** Look for keywords like "Adenocarcinoma of Pancreas," "Disseminated Intravascular Coagulation (DIC)," or "Cachexia." * **Libman-Sacks Endocarditis vs. NBTE:** Both are sterile, but Libman-Sacks (associated with SLE) features vegetations on *both* sides of the valve leaflets and chordae tendineae [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, p. 568.

Q: McCallum's patch is diagnostic of which condition?

Rheumatic endocarditis. **MacCallum’s Patch** is a classic morphological feature of **Rheumatic Heart Disease (RHD)** [1]. It represents an area of endocardial thickening caused by the mechanical trauma of regurgitant blood jets. 1. **Why Rheumatic Endocarditis is correct:** In Acute Rheumatic Fever, endocarditis primarily affects the valves, but it can also involve the mural endocardium [1]. MacCallum’s patch is typically found in the **posterior wall of the left atrium**, just above the posterior leaflet of the mitral valve. It occurs due to subendocardial inflammation (Aschoff bodies) followed by fibrosis, exacerbated by the "jet effect" of mitral regurgitation [1]. [1] 2. **Why other options are incorrect:** * **Infective Endocarditis:** Characterized by large, friable, and bulky **vegetations** (verrucae) on the valve leaflets, which may lead to perforation or abscess, but not MacCallum’s patches [1]. * **Myocardial Infarction:** Involves coagulative necrosis of the myocardium due to ischemia. * **Tetralogy of Fallot:** A congenital cyanotic heart disease characterized by four specific anatomical defects (VSD, pulmonary stenosis, overriding aorta, and RVH). **High-Yield Clinical Pearls for NEET-PG:** * **Aschoff Bodies:** The pathognomonic microscopic feature of RHD (contains Anitschkow cells/Caterpillar cells) [1]. * **Location:** MacCallum’s patch is most common in the **Left Atrium**. * **Vegetations in RHD:** Small, sterile, friable, and arranged in a **row along the line of closure** of the valves [1]. * **Fish-mouth/Button-hole deformity:** Refers to the chronic stage of RHD with mitral valve stenosis [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Heart, pp. 566-568.

Question 1

What is the most common site of myocardial infarction?

Accepted Answer

Anterior wall of left ventricle

Answer

Posterior wall of left ventricle

Answer

Posterior wall of right ventricle

Answer

Inferior wall of left ventricle

Question 2

A 10-year-old boy died of acute rheumatic fever. All of the following can be expected at autopsy EXCEPT:

Accepted Answer

Rupture of chordae tendinae

Answer

Ashoff nodules

Answer

McCallum patch

Answer

Fibrinous pericarditis

Question 3

A 25-year-old man suffers a sudden cardiac arrest and is resuscitated. His vital signs are normal on examination. Echocardiography reveals a normal left ventricle but marked thinning and dilation of the right ventricle. MRI of his chest shows extensive fibrofatty replacement of the myocardium without inflammation. What is the most likely cause for these findings?

Accepted Answer

Arrhythmogenic right ventricular cardiomyopathy

Answer

Chagas disease

Answer

Hypertension

Answer

Long QT syndrome

Question 4

In which of the following conditions are vegetations friable and easily detachable from the cardiac valves?

Accepted Answer

Infective endocarditis

Answer

Rheumatic fever

Answer

Rheumatoid heart disease

Answer

Systemic lupus erythematosus (SLE)

Question 5

When do neutrophils appear in myocardial infarction?

Accepted Answer

12-24 hours

Answer

Less than 4 hours

Answer

4-12 hours

Answer

1-3 days

Question 6

All of the following are true regarding marantic endocarditis except?

Accepted Answer

Affects damaged valves

Answer

Vegetation may embolize

Answer

Vegetations along the line of closure of leaflets

Answer

May be associated with hypercoagulable states

Question 7

McCallum's patch is diagnostic of which condition?

Accepted Answer

Rheumatic endocarditis

Answer

Infective endocarditis

Answer

Myocardial infarction

Answer

Tetralogy of Fallot

Question 8

Which of the following is true about Libman-Sacks endocarditis?

Accepted Answer

Vegetations are on either side of the valve leaflet

Answer

Vegetations are along the line of valve closure

Answer

Vegetations are non-friable

Answer

Organisms are consistently seen in the vegetations

Question 9

Which of the following does NOT cause coronary occlusion?

Accepted Answer

Organization of a thrombus

Answer

Atheromatous narrowing of the vessel

Answer

Atheromatous narrowing of the vessel

Answer

Rupture of an atheromatous plaque into the lumen

Question 10

All the statements regarding atherosclerosis are true, except:

Accepted Answer

Common site is the anterior wall of the right ventricle.

Answer

Naked eye changes are not visible for the first 12 hours.

Answer

Triphenyl tetrazolium chloride can help in detecting infracted area.

Answer

Most commonly involves the left coronary artery.

Cardiac Pathology — MCQs

Cardiac Pathology — MCQs

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