When performing a standard 12-lead ECG, where should the V4 precordial lead be placed?
- A.4th intercostal space, right sternal border
- B.5th intercostal space, left midclavicular line
- C.5th intercostal space, anterior axillary line
- D.4th intercostal space, left sternal border
Show answer & rationale
Correct answer
B. 5th intercostal space, left midclavicular line
Rationale
B is correct: V4 is placed at the 5th intercostal space along the left midclavicular line. This is the same anatomical landmark as the apical pulse location. V4 must be placed correctly before V5 and V6, as they are positioned relative to V4. A is incorrect: This describes V1 placement (4th ICS, right sternal border). C is incorrect: The 5th ICS anterior axillary line describes V5 placement. D is incorrect: The 4th ICS left sternal border describes V2 placement.
Key concepts
12-lead ECGPrecordial lead placementV4 electrode position