A 12-Lead Electrocardiogram (ECG) is a diagnostic test that records the heart's electrical activity from multiple angles using 10 electrodes placed on the skin. The test provides a comprehensive view of the heart's rhythm, rate, and electrical impulses, helping to identify abnormalities such as arrhythmias, ischemia, or heart attacks. It is performed by attaching electrodes to the chest and limbs, which transmit electrical signals to an ECG machine that produces a series of waveforms for analysis. This test is commonly used in situations such as chest pain, shortness of breath, unexplained dizziness, or fainting, as well as for routine screening in individuals with risk factors for heart disease. It is also crucial in monitoring patients with known heart conditions or assessing those undergoing treatments that may affect the heart. Additionally, it is frequently administered in emergency settings to diagnose acute cardiac events like heart attacks or arrhythmias.

The recommended schedule for a 12-lead ECG varies by age and risk factors. It is typically part of routine screening for individuals over 40, especially those with risk factors for cardiovascular disease, but may be administered earlier in individuals with a family history of heart disease or symptoms suggesting heart issues. For those under 40, it is generally not performed unless symptoms or risk factors indicate a need.