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isovolumic การใช้

ประโยคมือถือ
  • An increase in contractility is manifested as an increase in dP / dtmax during isovolumic contraction.
  • The contracting ventricles become closed chambers again and this phase is termed as " isovolumic contraction ".
  • Consequently, this initial phase of ventricular systole is known as isovolumic contraction, also called isovolumetric contraction.
  • Hence, dP / dtmin has been used as a valuable tool in the analysis of isovolumic relaxation.
  • The constant backflow of blood through the leaky aortic valve implies that there is no true phase of isovolumic relaxation.
  • The constant backflow of blood through the leaky mitral valve implies that there is no true phase of isovolumic contraction.
  • Likewise, an increase in diastolic function or an increase in relaxation ( lusitropy ) causes increased dP / dtmin during isovolumic relaxation.
  • There is also no true period of isovolumic contraction because some LV blood flows back into the left atrium through the leaky mitral valve.
  • The total area bound by the PV loop is the mechanical energy ( cardiac preload, and results in a left-shift and loss of the normal the isovolumic contraction line.
  • When the LV begins to contract and develop pressure, blood is still entering the LV from the aorta ( since aortic pressure is higher than LV pressure ), implying that there is no true isovolumic contraction.
  • Since the atrioventricular valves remain closed at this point, there is no change in the volume of blood in the ventricle, so the early phase of ventricular diastole is called the isovolumic ventricular relaxation phase, also called isovolumetric ventricular relaxation phase.
  • Left ventricular diastolic function can be determined through echocardiography by measurement of various parameters such as the E / A ratio ( early-to-atrial left ventricular filling ratio ), the E ( early left ventricular filling ) deceleration time, and the isovolumic relaxation time.
  • "' Isovolumic relaxation time "'( IVRT ) is an interval in the cardiac cycle, from the aortic component of the second heart sound, that is, closure of the aortic valve, to onset of filling by opening of the mitral valve.