Sino Atrial Block

The sinus node depolarises normally but there is an intermittent failure of conduction of the impulse to the atrial myocardium (exit block) with failure of atrial depolarization

Source

• Simon Carley, “Case B3. Sino Atrial Block. St Emlyn’s ECG Library,” in St.Emlyn’s, October 28, 2018, https://www.stemlynsblog.org/ecg-library-st-emlyns/case-b2-sino-atrial-block-st-emlyns-ecg-library/.