Infarction
• Is due to Pericarditis whose causes include:- bacterial and viral pericarditis, myocardial infarction, rheumatic fever, connective tissue disorder, trauma, uraemia
What our notes say
- • Is due to Pericarditis whose causes include:- bacterial and viral pericarditis, myocardial infarction, rheumatic fever, connective tissue disorder, trauma, uraemia (Cardiovascular system examination revised 2012 — Past Paper Questions & Answers)
- Myocardial infarction is associated with faster utilisation of creatine phosphate (bchem EOY 2011 — Past Paper Questions & Answers)
- A 51-year-old man is hospitalized for acute myocardial infarction. (renal pathology — Past Paper Questions & Answers)
- A 60-year-old woman is admitted with sudden onset of chest pain and is diagnosed with an acute myocardial infarction. (renal pathology — Past Paper Questions & Answers)
- Secondary lung abscess: arises on underlying disease: bronchial obstruction (tumour, foreign body), bronchiectasis, septic emboli, TB cavity, pulmonary infarction, immunosuppression. (Lung Abscess)
- Low cardiac output: heart failure, myocardial infarction, arrhythmias, cardiac tamponade, pulmonary embolism. (Junior Clerkship in Internal Medicine (MBIM4100) main exam, Paper One: 31 Januar)
Study material on Infarction
- CARDIOVASCULAR PATHOLOGY
- CNS PATHOLOGY
- Cerebrovascular Disease: Stroke, Ischemia & Hemorrhage Explained
- Cardiovascular system examination revised 2012
- CARDIOVASCULAR PATHOLOGY
- Chemical Pathology MCQs: Clinical Chemistry, Endocrine & Renal
- Clinical Enzymes: Functions and Applications
- CLINICAL BIOCHEMISTRY LAQs & SAQs
- GASTROINTESTINAL PATHOLOGY (Part 2)
- Comprehensive Heart Pathology Notes 🫀
- Cardiovascular Disease and Biochemical Markers MCQs
- Weekly Pathology Exam - June 19, 2026 (Section A: MCQs)
Practice questions on Infarction
A 55-year-old man has a history of hypercholesterolemia with coronary artery disease and suffered a myocardial infarction 2 years ago. He now presents with crushing substernal chest pain. Which of the following laboratory tests is most useful in diagnosing the cause of his chest pain?
- Increased white blood cell count
- Elevated sedimentation rate
- Decreased serum complement
- Increased serum troponin
- Decreased platelet count F. Increased serum cholesterol
Answer: D. Troponins are released from the damaged striated muscle. Cell damage leads to leakage of intracellular contents, such as enzymes or other proteins. Some of these are more specific for certain tissues to aid in diagnosis. ---
A patient receives a COX-2 selective inhibitor for chronic arthritis but develops a myocardial infarction. What best explains this adverse effect?
- COX-2 inhibition increases leukotriene synthesis via shunting of arachidonic acid
- Selective inhibition of endothelial PGI2 production without affecting platelet TxA2 favors thrombosis
- COX-2 inhibitors enhance neutrophil adhesion to vascular endothelium
- Inhibition of COX-2 increases production of pro-inflammatory cytokines
- COX-2 blockade impairs hepatocyte regeneration leading to coagulopathy
Answer: B. This is a critical clinical point about selective COX-2 inhibitors. Endothelial cells produce prostacyclin (PGI2) via COX-2, which is a vasodilator and inhibits platelet aggregation. Platelets produce thromboxane A2 (TxA2) via COX-1, which promotes vasoconstriction and platelet aggregation. Selective COX-2 inhibitors block endothelial PGI2 production but leave platelet TxA2 production intact (since platelets use COX-
What is the most common histological change seen within 24 hours following a myocardial infarction?
- Pallor and oedema
- Increased collagen deposition
- Liquefactive necrosis
- Disintegration of dead myofibers
- Neutrophilic infiltration
Answer: D. Within 24 hours of a myocardial infarction, the primary histological change is coagulative necrosis, characterized by the loss of nuclei and striations, and disintegration of dead myofibers.
In pulmonary embolism, infarction occurs in only about 10% of cases because
- Most emboli are too small to cause significant obstruction
- The lung has dual blood supply from pulmonary and bronchial arteries
- Fibrinolysis rapidly resolves most emboli before infarction
- Collateral circulation from adjacent lung segments prevents necrosis
Answer: B. The lung is protected from infarction by its dual blood supply: pulmonary arteries, bronchial arteries, and direct oxygenation from alveolar air. Infarction only occurs when this is compromised. ---
Which of the following is the most specific marker for myocardial infarction?
- CK-MB
- Troponin I
- Myoglobin
- LDH Correct
Answer: B. Troponin I is highly specific for cardiac muscle and remains elevated longer than other markers, making it gold standard for MI diagnosis. ---
Which cardiac biomarker has the SHORTEST time to return to normal levels after myocardial infarction?
- Troponin I
- CK-MB
- Troponin T
- NT-proBNP
Answer: B. ** CK-MB typically returns to normal within a few days after myocardial infarction, helping determine the timing of myocardial injury. Troponins remain elevated for several days longer. ---