Pre-ejection ventricular phase starts
Aortic valve open pulmonary valve closed
Aortic valve closed pulmonary valve open
Aortic and pulmonary valve are open
Aortic and pulmonary valve closed
C. i.e. (Aortic and pulmonary valve are open) (565-Ganong 2nd) (509-Ganong 23rd)* When the aortic and pulmonary valves open the phase of ventricular ejection begins. Ejection is rapid at first, slowing down as systole progress* The ejection fraction is valuable index of ventricular fraction*** The duration of each cardiac cycle is about 0.8 sec** (systole 0.27 sec & Diastole 0.53 sec)* Dicrotic notch - The pulmonary artery pressure curve also has a dicrotic notch produced by the closure of the pulmonary valve i.e. second heart sound*** Isovolumetric contraction - the first phase of ventricular systole. Immediately after atrial systole the A V are closed due to increase in ventricular pressure the semilunar valve are already closed**. Now the ventricles contracts as closed cavities. Only the tension increases in-ventricular* First heart sound occurs during the period of isovolumetric contraction**.* Fourth heart sound is caused by - Biventricular filling**
Heart, Circulation, and Blood