https://derangedphysiology.com/main/required-reading/cardiology/Chapter%201.1.8/ecg-localisation-coronary-artery-territories

https://www.nottingham.ac.uk/nursing/practice/resources/cardiology/function/bipolar_leads.php

Now we have 12 leads, we need to know which regions of the heart each lead is looking at and what groups they make up.

Regions of the Heart

• AVL is on the left wrist or shoulder and looks at the upper left side of the heart.
• Lead l travels towards AVL creating a second high lateral lead.
• AVf is on the left ankle or left lower abdomen and looks at the bottom, or inferior wall, of the heart.
• Lead ll travels from AVr towards AVf to become a 2nd inferior lead
• Lead lll travels from AVL towards AVf to become a 3rd inferior lead.
• V2 V3 and V4 look at the front of the heart and are the anterior leads.
• V1 is often ignored but if changes occur in V! and V2 only, these leads are referred to as Septal leads.
• V5 and V6 look at the left side of the heart and are the lateral leads.

The ECG below shows where these leads are when printed.

 https://www.nottingham.ac.uk/nursing/practice/resources/cardiology/resources/ecg_regions.pdf