How many standard ECG leads are used in a typical ECG setup?

In a typical ECG setup, 12 standard leads are used to provide a comprehensive view of the heart's electrical activity. These leads include 6 limb leads (I, II, III, aVR, aVL, and aVF) and 6 chest leads (V1 through V6). Using 12 leads allows for better localization of potential heart issues, as different leads capture electrical activity from various angles of the heart. This extensive coverage is crucial for identifying conditions such as arrhythmias, ischemia, and other cardiac anomalies, making the 12-lead ECG a standard practice in clinical settings. Other options do not encompass the complete standard used in medical practice for an accurate assessment of heart function.