Cardiac Pathology Practice Questions

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

Anterior wall of the left ventricle. ### Explanation **1. Why the Correct Answer is Right:** The **Anterior wall of the left ventricle** is the most common site for myocardial infarction (MI). This is because it is supplied by the **Left Anterior Descending (LAD) artery**, which is the most frequently occluded vessel in the coronary anatomy (often referred to as the "widow-maker"). The left ventricle has the highest muscle mass and metabolic demand, making its anterior wall particularly susceptible to ischemic injury when the LAD is compromised [1]. **2. Why the Other Options are Incorrect:** * **Posterior wall of the right ventricle:** Isolated Right Ventricular (RV) infarctions are rare. RV involvement usually occurs as an extension of an inferior wall MI. The RV has lower oxygen demand and better collateral supply compared to the left ventricle [3]. * **Posterior wall of the left ventricle:** This is typically supplied by the Left Circumflex (LCX) artery or the Right Coronary Artery (RCA) [1]. While significant, LCX occlusions are less frequent than LAD occlusions. * **Inferior wall of the left ventricle:** This is the second most common site of MI, usually resulting from occlusion of the **Right Coronary Artery (RCA)**. While common, it statistically trails behind anterior wall MIs. **3. Clinical Pearls for NEET-PG:** * **Vessel Frequency:** LAD (40-50%) > RCA (30-40%) > LCX (15-20%). * **ECG Localization:** * Anterior wall: Leads V1–V4 [2]. * Inferior wall: Leads II, III, aVF [2]. * Lateral wall: Leads I, aVL, V5, V6. * **Complications:** Anterior MIs are more likely to lead to **heart failure** and cardiogenic shock due to the large area of muscle affected. Inferior MIs are frequently associated with **bradyarrhythmias** (AV blocks) because the RCA supplies the SA and AV nodes.

Q: All of the following arteries are common sites of occlusion by a thrombus, except?

Marginal artery. The question tests the knowledge of the clinical significance and frequency of occlusion in the coronary arterial system. Myocardial infarction (MI) most commonly results from the occlusion of the major branches of the coronary arteries. [1] **Why Marginal Artery is the Correct Answer:** The **Marginal artery** (specifically the right marginal branch of the RCA) is the least common site for clinically significant thrombotic occlusion among the options provided. While it supplies the right ventricle, its occlusion is rarely the primary cause of a major MI compared to the "Big Three" coronary branches. In clinical practice, isolated marginal artery disease is less frequent and often less hemodynamically catastrophic than proximal major branch disease. **Analysis of Incorrect Options:** * **Left Anterior Descending (LAD) Artery:** This is the **most common** site of coronary occlusion (approx. 40-50%). It is famously known as the "Widow Maker" because it supplies the anterior wall of the left ventricle and the anterior 2/3rd of the interventricular septum. * **Right Coronary Artery (RCA):** This is the **second most common** site (approx. 30-40%). Occlusion typically leads to inferior wall MI and can involve the SA and AV nodes, causing arrhythmias. * **Circumflex Coronary Artery:** This is the **third most common** site (approx. 15-20%). It supplies the lateral wall of the left ventricle. **NEET-PG High-Yield Pearls:** 1. **Frequency Hierarchy:** LAD > RCA > Circumflex. 2. **Artery of Sudden Death:** Left Anterior Descending (LAD). 3. **Coronary Dominance:** Determined by which artery gives rise to the **Posterior Interventricular Artery** (PDA). In 70-85% of individuals, it is the RCA (Right Dominant). 4. **SA Node Supply:** Usually by the RCA (60%); **AV Node Supply:** Usually by the RCA (90%). [1]

Question 1

A young asymptomatic female is observed to have a midsystolic click on routine examination. Which valvular change is most likely responsible?

Accepted Answer

Myxomatous degeneration

Answer

Aschoff bodies

Answer

Calcific degeneration

Answer

Ruptured chordae tendinae

Question 2

Atrial myxoma is associated with elevated serum levels of which interleukin?

Accepted Answer

IL-6

Answer

IL-1

Answer

IL-4

Answer

None of the above

Question 3

SLE is characterized by vegetations on the mitral and tricuspid valves. These vegetations are known as:

Accepted Answer

Libman-Sacks endocarditis

Answer

Salmon patch

Answer

Janeway lesions

Answer

Osler nodes

Question 4

A 20-year-old male patient collapses and dies suddenly while jogging. Autopsy reveals significant left ventricular hypertrophy predominantly affecting the septum, with no valvular abnormalities. The patient's family history is significant for an uncle who died suddenly at the age of 20 years. Assuming this patient died of an inherited condition, what is the most likely finding on gross examination of the heart?

Accepted Answer

Hypertrophic cardiomyopathy

Answer

Dilated cardiomyopathy

Answer

Restrictive cardiomyopathy

Answer

Aortic dissection

Question 5

In Rheumatic fever, fibrinoid necrosis occurs in which of the following structures?

Accepted Answer

Collagen

Answer

Myocardium

Answer

Pericardium

Answer

Endocardium

Question 6

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 7

What is the most common tumor of heart valves?

Accepted Answer

Papillary fibroelastoma

Answer

Malignant fibrous histiocytoma

Answer

Angiosarcoma

Answer

Rhabdomyosarcoma

Question 8

All of the following arteries are common sites of occlusion by a thrombus, except?

Accepted Answer

Marginal artery

Answer

Left anterior descending artery

Answer

Right coronary artery

Answer

Circumflex coronary artery

Question 9

A 30-year-old woman with a history of intravenous drug abuse presents with rapidly progressive malaise, fever, and chills. Physical examination reveals subungual splinter hemorrhages and a systolic murmur. Blood cultures are positive for Staphylococcus aureus. The patient died of myocardial infarction on her third hospital day. What was the underlying condition that led to the patient's demise?

Accepted Answer

Acute infective endocarditis

Answer

Carcinoid heart disease

Answer

Libman-Sacks endocarditis

Answer

Nonbacterial thrombotic endocarditis

Question 10

What is the characteristic pathological finding in carcinoid of the heart?

Accepted Answer

Fibrous endocardial thickening of the right ventricle and tricuspid valve

Answer

Collagen deposition in the wall of the right ventricle and tricuspid valve

Answer

Interstitial fibrous thickening of the right ventricle and pulmonic valve

Answer

Mononuclear inflammatory infiltrate in the wall of the right atrium

Cardiac Pathology — MCQs

Cardiac Pathology — MCQs

On this page

Practice by Chapter

Want unlimited practice?