For proper placement of V5, where should the electrode be positioned?

The proper placement of V5 for an electrocardiogram (ECG) is specifically located at the same horizontal level as V4, but positioned more laterally to provide optimal readings from the left ventricle. This electrode should be placed at the left anterior axillary line (just lateral to the midaxillary line) at the fifth intercostal space, ensuring it captures the electrical activity of the heart effectively. This placement is crucial for accurately assessing the heart's function, especially for detecting issues like left ventricular hypertrophy or ischemia.

Positioning V5 at the arm joint or where it meets the chest—just lateral to V4—ensures that the electrode maintains that necessary horizontal alignment while also gaining a perspective that increases the identification of lateral heart activities. This axial placement naturally complements surrounding electrodes, thereby enhancing the ECG's diagnostic capabilities, particularly when interpreting waveforms from the left side of the heart.

In contrast, placing V5 in the other suggested locations would not align with the standard protocol for ECG electrode placement. For instance, positioning it on the midaxillary line would not sufficiently capture the electrical signals from the heart's lateral surface. Similarly, placing it at the left side of the neck or near the lower abdomen would be