During ventricular ejection, descent of the ventricular base lowers atrial pressure and thus assists in atrial filling. Filling of the atria from the veins results in a v wave on the atrial and venous pressure tracing. When the mitral and tricuspid valves open, blood stored in the atria empties into the ventricles.

Is the mitral valve closed during ventricular ejection?

Contraction (systole) begins after an approximately 50 ms delay and results in closure of the mitral valve. The left ventricle contracts isovolumetrically until the ventricular pressure exceeds the systemic pressure, which opens the aortic valve and results in ventricular ejection.

What happens during ventricular depolarization?

Ventricular depolarization will lead to ventricular contraction and the start of systole. Remember that systole is the cardiac phase in which the heart, especially the ventricles, contracts to move blood forward into the pulmonary artery and aorta.