Normal jugular venous pressure waveform

The three positive waves are labeled by convention as waves a, c, and v. The a wave is generated by atrial contraction, the c wave is caused either by transmission of the carotid arterial impulse through the external and internal jugular veins or by the tricuspid valve bulging into the right atrium in early systole, and the v wave is caused the passive increase in pressure and volume of the right atrium as it fills in late systole and early diastole. The descents from a and c are considered x descents, whereas the descent after the v wave is the y descent. (Source: Stanford Medicine. Courtesy of Wikimedia Commons. Public domain.)