Final answer:
The 12-lead ECG uses 10 electrodes: six on the chest and four on the limbs to measure the heart's electrical activity from different angles. These leads help in diagnosing heart conditions by detecting infarcts and gradual changes over time. Advanced ECG technology enables portable monitoring outside clinical environments.
Step-by-step explanation:
The 12-lead ECG is a fundamental tool in the medical field for evaluating the electrical activity of the heart. A standard 12-lead ECG utilizes 10 electrodes with six of these electrodes placed strategically on the chest and four placed on the limbs. The placement of these electrodes allows for the recording of different electrical viewpoints, referred to as leads, which are essentially the voltage differences measured between various combinations of these electrodes. The standard 12 leads are labeled as Lead I, II, III, aVR, aVL, aVF (limb leads), and V1 through V6 (chest leads). Each lead monitors the heart's electrical activity from different angles, providing a comprehensive view of the heart's function. Infarcts and subtle changes in heart tissue can be identified by analyzing these leads, making the ECG a vital diagnostic tool for detecting heart abnormalities.
Modern ECG technology has progressed to the extent that portable ECG monitors can now be worn and used outside of hospital settings, allowing continuous monitoring of heart electrical activity. By comparing recent ECGs to older ones, clinicians can potentially detect gradual changes in heart function or monitor the status of known conditions.