Which lead is located midway between V2 and V4?

The lead that is located midway between V2 and V4 is V3. In the context of an electrocardiogram (ECG), the precordial leads are placed on the chest to provide information about the heart's electrical activity.

The positioning of these leads is systematic: V1 is placed in the right fourth intercostal space, while V2 is in the left fourth intercostal space. V4 is positioned in the left fifth intercostal space at the midclavicular line. Given this layout, V3 is strategically placed between V2 and V4, positioned in the left fifth intercostal space but closer to the midline, effectively serving as a bridge between the two.

This understanding of the lead placements is crucial for interpreting an ECG accurately, as the spatial relationship of the leads reflects different angles and views of the heart's electrical activity.