63bf4c4b-9b47-4eaa-a919-35a7761fb531.jpeg
Explain this
analyse_media
Reading File
Here is a full explanation of the image:
Location of MI by ECG Leads
This table is a core cardiology reference that maps ECG leads to the anatomical wall of the heart they "look at." When that wall is infarcting, the corresponding leads will show ST-elevation (or reciprocal changes).
The Full Table
| Lead | Wall of the Heart |
|---|---|
| I | Lateral |
| II | Inferior |
| III | Inferior |
| aVR | (Cavity / right-sided - not directly used for wall localization in standard MI mapping) |
| aVL | Lateral (high) |
| aVF | Inferior |
| V1 | Septal |
| V2 | Septal |
| V3 | Anterior |
| V4 | Anterior |
| V5 | Lateral (low) |
| V6 | Lateral (low) |
The 4 Major MI Territories
The handwritten red markings on the image group the leads into territories:
1. Inferior Wall MI
- Leads: II, III, aVF
- Supplied by: Right Coronary Artery (RCA) in most people
- ST elevation in II, III, aVF = inferior STEMI
- Reciprocal depression often seen in I and aVL
2. Septal MI
- Leads: V1, V2
- Supplied by: Left Anterior Descending (LAD) - septal perforators
- Loss of septal Q waves, ST changes in V1-V2
3. Anterior MI
- Leads: V3, V4
- Supplied by: LAD
- The most dangerous territory - large muscle mass at risk
- Anterior + septal together = "anteroseptal MI" (V1-V4)
4. Lateral Wall MI
- Leads: I, aVL (high lateral) and V5, V6 (low lateral)
- Supplied by: Left Circumflex Artery (LCx) or diagonal branches of LAD
- Combined anterior + lateral = "anterolateral MI" (common pattern)
Practical Memory Aid (the handwritten "Ant." and "Lateral" labels)
The student has annotated:
- "Ant." below V4 - confirming anterior territory
- "Lateral" below V5 - confirming lateral territory
- "Post." near the top left - posterior MI is the "hidden" territory (not directly seen, detected by reciprocal tall R waves and ST depression in V1-V2, confirmed with posterior leads V7-V9)
Quick Clinical Summary
| Territory | Leads | Artery |
|---|---|---|
| Inferior | II, III, aVF | RCA |
| Septal | V1, V2 | LAD (septal perforators) |
| Anterior | V3, V4 | LAD |
| Lateral (high) | I, aVL | LCx / diagonal |
| Lateral (low) | V5, V6 | LCx |
| Posterior | Reciprocal in V1-V2 | RCA / LCx |
The Side Question in the Image
The handwritten question asks: "What is the importance of a routine chest X-ray on a patient admitted [for MI]? identify?"
Answer written: Pulmonary edema
This is correct - a chest X-ray in an MI patient is done to assess for pulmonary edema (cardiogenic), which indicates left heart failure and elevated pulmonary venous pressure. Other findings you can assess include cardiomegaly, pleural effusions, and widened mediastinum.
This is a shared conversation. Sign in to Orris to start your own chat.