Certified Medical Assistant (CMA AAMA)Procedures, Examinations and DiagnosticsMedium
A medical assistant is applying chest electrodes for a 12-lead EKG. Where should the V1 electrode be placed?
- ASecond intercostal space, right sternal border
- BFifth intercostal space, left midclavicular line
- CFourth intercostal space, left sternal border
- DFourth intercostal space, right sternal border
Show answer & explanationAnswer & explanation
Correct answer: D. Fourth intercostal space, right sternal border
V1 is placed at the fourth intercostal space at the right sternal border. V2 is placed at the fourth intercostal space at the left sternal border, and the remaining chest leads follow sequentially toward the left side of the chest.
Why the other options are wrong
- A. Second intercostal space is not used for any standard chest lead placement.
- B. This describes V4 placement, at the fifth intercostal space midclavicular line.
- C. This is the correct location for V2, not V1.
V1 Chest Lead Placement
V1 is positioned at the fourth intercostal space along the right sternal border, serving as the starting reference point for placing the remaining precordial leads.
- V1: 4th ICS, right sternal border
- V2: 4th ICS, left sternal border
- V4: 5th ICS, midclavicular line; V6: midaxillary line same level as V4
Memory trick: 'V1 right, V2 left—same rib, different side' then walk left to V6.