Histopathological examination of cardiac tissue from a post-MI patient shows a predominant neutrophilic infiltrate. This finding corresponds to which post-infarction time window?

1. A

   A. 2–3 months

2. B

   B. 12–24 hours

3. C

   C. 1–3 days

4. D

   D. 7–10 days

Appeared in: INI-CET EXAM -2026

Explanation

• Following a myocardial infarction, the body triggers an acute inflammatory response to remove the dead heart muscle cells.
• Neutrophils are the first type of white blood cell to arrive at the site of injury.
• The infiltration of neutrophils becomes most intense and they are the 'predominant' cell type between 1 and 3 days post-MI.
• This massive influx of neutrophils is a key histological marker for dating an MI to this specific time frame.

Why Other Options Were Wrong

• Option A: At 2–3 months, the healing process is complete. The necrotic tissue has been replaced by a dense, collagenous scar. Acute inflammatory cells like neutrophils are long gone.
• Option B: During the 12–24 hour window, neutrophils are just beginning to infiltrate the area. Their presence is considered 'early' and they have not yet reached the peak numbers needed to be described as 'predominant'.
• Option D: By 7–10 days, the inflammatory response has shifted. Most neutrophils have died off and are being cleared away. Macrophages are now the predominant cell type, responsible for phagocytosing debris and beginning the repair process by forming granulation tissue.

Related Visual

Clinical Relevance

• Nursing practice connection: Use the key finding related to Histological timeline of myocardial infarction healing to guide bedside assessment, documentation, and the next nursing action.
• Understanding this pathological timeline is crucial for forensic pathologists to estimate the age of a myocardial infarction during an autopsy.
• Clinically, the period of maximal neutrophilic infiltration and necrosis (1-3 days) is when the heart wall is at its weakest. This knowledge alerts nurses to monitor for signs of life-threatening complications like cardiac rupture and tamponade.
• What if? If the question had asked for the predominant cell type at 7 days post-MI, the correct answer would be macrophages, which are responsible for cleanup and initiating tissue repair.

How to Approach the Question

• First, identify the core of the question: it asks for the specific time frame for a particular histological finding ('predominant neutrophilic infiltrate') after an MI.
• Recognize this as a factual recall question based on the pathophysiology of wound healing in the heart.
• Recall the general sequence of inflammatory cells in tissue repair: neutrophils arrive first for acute inflammation, followed by macrophages for cleanup and to orchestrate repair.
• Focus on the keyword 'predominant'. This implies the peak of activity, not just the beginning or end.
• Evaluate the options based on this sequence: 12-24 hours is too early (onset), 7-10 days is too late (macrophage phase), and 2-3 months is the final scar stage. This leaves 1-3 days as the logical window for peak neutrophilic activity.

Concept Tested & Keywords

• Concept Tested: Histological timeline of myocardial infarction healing
• Stem keywords: Histopathological examination, cardiac tissue, post-MI, neutrophilic infiltrate
• Lead-in keywords: predominant, post-infarction time window
• Negative lead-in flag: false

Question ID

QUF1Vim-gOi9OhMbsl4T_O

Copy ID

Reference Book

E6 Pathology- ROBBINS & COTRAN PATHOLOGIC BASIS OF DISEASE 10TH Ed p. 551-553

E6 PATHOLOGY QUICK REVIEWBased on Harsh Mohan Textbook of PATHOLOGY p. 196-198