What are leads I, II, and III collectively referred to in EKG?

Leads I, II, and III are referred to as standard leads in electrocardiography. These leads are part of the limb leads and are derived from the placement of electrodes on the patient's arms and legs. They provide fundamental information about the heart's electrical activity from different angles.

The standard leads are essential for interpreting the heart's rhythm and identifying abnormalities such as arrhythmias and myocardial infarctions. They form the basis for the 12-lead EKG, which includes additional leads for a more comprehensive view of the heart's electrical activity.

Understanding this classification is crucial for those interpreting EKGs, as it allows clinicians to quickly identify and analyze the heart’s electrical pattern and any potential issues. The term "standard leads" emphasizes their foundational role in EKG assessment when compared to other types of leads, which might serve different purposes or be used in specific clinical contexts.