Where is the V1 electrode placed for a 12 lead ECG?

The V1 electrode for a 12-lead ECG is correctly placed in the fourth intercostal space at the right side of the sternum. This placement allows for optimal visualization of the electrical activity arising from the heart, particularly the right side. The V1 position is technically important because it provides information about the septal and anterior walls of the heart.

Placing the electrode in the fourth intercostal space at the right sternum allows for a standard reference point that helps to create a consistent and comparable electrical profile of the heart. This standard placement is crucial for accurately diagnosing conditions such as myocardial infarction.

Other electrode placements mentioned in the options would not provide the same critical views of cardiac electrical activity. For instance, electrodes located on the left side of the sternum or in the mid-axillary line would not accurately capture the electrical signals from the right ventricle or the interventricular septum, thus making them less effective for a thorough cardiac assessment.