Where is the V6 electrode placed in a standard 12-lead ECG?

• A. Left anterior axillary line, same level as V4
• B. Left midaxillary line, same level as V4
• C. Right midaxillary line, same level as V4
• D. Left posterior axillary line, same level as V4

Answer: (B)

This question tests how the chest leads are positioned on the chest for a standard 12-lead ECG, focusing on the lateral position of V6. V6 is placed on the left side of the chest along the midaxillary line at the same horizontal level as V4. That level is the fifth intercostal space, where V4 sits at the left midclavicular line; V5 sits at the left anterior axillary line, and V6 sits farther laterally at the left midaxillary line, all aligned vertically with V4. This placement provides a view of the heart’s electrical activity from the lateral wall of the left ventricle. The other sites described would correspond to different leads (for example, the anterior axillary line is where V5 sits, the right side isn’t used for V6 in the standard setup, and the posterior axillary line relates to the posterior leads V7–V9 rather than V6).