P wave

How does the physiological excitation propagate in the atria?

Normally, the excitation of the heart starts in the sinus node. The sinus node is located in the right atrium. From here, the excitation first spreads throughout the right atrium itself, then into the left atrium, and then into the ventricles via the AV node. If this pattern of excitation formation and excitation propagation is visible in an ECG, we refer to the presence of a sinus rhythm.