Body & HealthHow it works

How ten electrodes become twelve views of the heart.

A standard ECG sticks ten electrodes on limbs and chest and computes twelve leads from them – twelve viewing angles. The P wave shows atrial depolarisation, the QRS complex ventricular depolarisation, the T wave their repolarisation. Willem Einthoven won the Nobel Prize for it in 1924.

Useful: The spikes aren't heartbeats but the electrical waves that trigger them.

Source: en.wikipedia.org

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