For An adequate assessment of LV diastolic function is necessary to know the physiology of the diastolic phase of the cardiac cycle .
AT diastole there are four periods :
. phase relaxation : on closing of the aortic valve stem Pan to the opening of the mitral valve ( phase 1);
. early rapid filling phase : from the opening of the mitral valve to the end of filling ( fa for 2);
. phase of diastasis — equilibrium ( phase 3);
. phase systole predserdiy- active cut of auricles ( phase 4).
The first two phases correspond to the relaxation of the ventricular myocardium ( energy-intensive process ). Tre tya and The fourth phase reflects the passive extension of the myocardium , depending on its rigidity . So way , allocate two major type dia stolicheskoy dysfunction :
slow relaxation ;
restrictive type .
Diastolic dysfunction occurs at connections with by Vyshen stiff LV , which leads to disruption of diastolic blood flow of LP at LV .
Scanning in the M-mode at the level of the mitral valve
AT normal movement PSMK at diastole has character hydrochloric M – shaped form ( with waves E and A ) With diastema netocrystalline dysfunction LV tour PSMK reduced , wave BUT becomes higher , than the wave E , that leads to reducing the E / A ratio . These changes OCU by previously increased rigidity LV and subsequent increase in pressureat LP . Indicated signs not are highly sensitive or specific for identify diastolic dysfunction .