What is unipolar lead in ECG?

A unipolar lead in an electrocardiogram (ECG) is a type of lead that records the electrical activity of the heart from a single positive electrode, with the reference point being a central terminal created by combining the outputs of multiple electrodes. Common examples include the augmented limb leads (aVR, aVL, aVF) and precordial leads (V1 to V6). These leads help provide a more detailed view of the heart's electrical activity, enhancing the diagnosis of various cardiac conditions. Unlike bipolar leads, which measure the voltage difference between two electrodes, unipolar leads focus on the potential at one site relative to a central reference.