How many leads are typically used in a standard 12-lead ECG?

A standard 12-lead ECG utilizes a total of 12 leads to provide a comprehensive view of the heart's electrical activity. These leads are derived from 10 electrodes placed on the body – six on the chest and four on the limbs. By combining these electrodes, the 12 leads generated allow healthcare providers to assess the heart's rhythm, identify potential abnormalities, and determine the presence of conditions such as ischemia or myocardial infarction.

The 12 leads include three standard limb leads (I, II, III), three augmented limb leads (aVR, aVL, aVF), and six chest leads (V1 through V6). The arrangement of these leads captures electrical impulses in different planes, providing vital information about the heart's structure and function from multiple angles. Understanding this setup is crucial for interpreting the ECG effectively and diagnosing cardiac issues accurately.