Isometric Ventricular contraction period:
As ventricular systole starts the atrioventricular valves (AV valves) of both ventricles synchronously close this produces the first heart sound At this time semilunar (SL) valves are also closed thus in the beginning of ventricular systole there are closed cavities and the ventricular pressure is mounting up without any decrease in its volume this is isometric contraction period its onset is marked by closure of AV valves and termination by opening of SL valves this period remains for 0.05 sec Intraventricular pressure is highest during this period
Rapid and slow ejection period::
After 0.05 sec isometric contraction period semilunar valves open and due to ventricular systole blood is ejected out into respective arteries this is rapid ejection period (0.15 sec) the intra ventricular pressure starts rising however intraventricular volume stepsdown and blood is poured out with maximum force in the late part of ventricular systole intraventricular pressure declines and blood is poured with slow speed this is called slow ejection period (0.1 sec)
Various events of cardiac Cycle
Atrial systole or Last rapid filling 0.10 Systole Diastole open close 4
Isometric ventricular contraction 0.05 Diastole systole close close 1
Rapid ejection and slow ejection 0.25 Diastole systole close open --
Prodiastolic 0.04 Diastole Diastole close open ---
Isometric ventricular relaxation 0.08 Diastole Diastole close close 2
Rapid inflow and slow inflow 0.28 Diastole Diastole open close 3
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