Myocardial contractility by dr najeeb biography

seconds in duration cycle

duration
It is 0.8
cardiac cycleTeartt Rate
of
The cardiac cycle is the performance of the human heart from
the beginning of one heartbeat to the beginning of the next
One cardiac cycle 1 systole 1 diastole
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In the next drawing the left atrium and ventricle events will
be presented

cnet.ir 1 phase Left atrium contraction

f During this phase mitral valve open
aortic valve close de
Stick fgfy
l It means that during atrial contraction
there is communication between the
left atrium and the left ventricle but
w there is no communication between the
left ventricle and aorta
It means for the left ventricle the input system is working
but output system is not working
Before the atrial Contraction occurs about 80 of Ventricular
filling is already done It means that atrial contraction
when it occurs it just adds the last 20 of ventricular filling
It is important to understand
of ventricular 1
80 filling is passive
it is not require atrial effort

The last 20 of ventricular filling is done

Qif
by active atrial contraction

when the left atrium will contract naturally the pressure

in the left atrium will increase slightly
The A wave is produced during the

if f
increase of pressure at the atria
due to atrial contraction
Fees Ye Éue
When atrium is contracting and
the pressure in atrium is increasing we must notice that
the mitral valve is open so it means all the pressure from
the atrium is easily communicated to the left ventricle
It means when pressure in the atrium increases
the the
blood moves into the ventricle and when it happens the
pressure is transferred to the left ventricle
So we can say that at this particular moment when atrium
is contracting just before the contraction of the atrium
the pressure at the ventricle equals to zero because it
is relaxed but as soon as contraction occurs it pushes the
last part of the blood into it and pressure start in