i read that the more the end diastolic volume in the heart increases, the ED pressure increases as well and the heart performance decreases. anyone can explain why?
but i'll try to unswer: the performance of the heart (i.e. ejection fraction is one of the indices) is related to the wall tension which is experienced the heart. the wall tension, which is given by laplace law, is in turn, inversely proportional to the wall thickness of the heart chamber and is directly proportional to the chamber size and the afterload (i.e. blood pressure most of the time). the higher the tension the higher the oxygen requirments and, optionally, the lower the cardiac performance (i.e. decrease in EF). the equation is as follow: tension= radius x pressure/wall thickness. the large EDV causes increase in the end diastolic pressure. this increase in pressure causes a stretch of the heart chamber
As with a rubber band, the more you strech it the harder it returns. That's how the myocardium reacts to the volume inserted to it. But there is a limit to strech and eventually the rubber band will tear as will the myocardium fail once stretched too much leading to a compensatory hypertrophy at the beggining and then a dilation and eventually a dilatative cardiomyopathy.
The more you fill a chamber the higher the pressure increases which is the force working to expand the chamber and eventually as above mentioned lead to its failure
if i understood correctly, end diastolic volume increases with decreasing cardiac performance cause,it increases the time duration of diastole so long duration long volume of blood volume in diastole right?
