isovolumic


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i·so·vol·u·mic

(ī'sō-vol-yū'mik),
Occurring without an associated alteration in volume, as when, in early ventricular systole, the muscle fibers initially increase their tension without shortening so that ventricular volume remains unaltered.
See also: isometric.
Synonym(s): isochoric, isovolumetric

i·so·vol·u·mic

(ī'sō-vol-yū'mik)
Occurring without an associated alteration in volume, as when, in early ventricular systole, the muscle fibers initially increase their tension without shortening so that ventricular volume remains unaltered.
See also: isometric
References in periodicals archive ?
[9] DecT: deceleration time; IVRT: isovolumic relaxation time; AHI: apnea- hypopnea index; OSA: obstructive sleep apnea.
Isovolumic contraction occurred under LVAD treatment with the LAAO cannulation site in the normal condition because of direct cannulation from the LA to the aorta, which completely distributed the blood, resulting in no change in the LV volume.
Therapeutic agents, symptoms, creatine kinase (CK, shown as open black circles in graph (a)), N-terminalpro b-type natriuretic peptide (NT-proBNP, shown as open gray circles in graph (a)), left ventricular posterior wall end diastole, percent of normal (LVPWD% N, shown as closed black triangles in graph (b)) and left ventricular diastolic diameter (LVDd, shown as closed gray triangles in graph (b)), and Tei index showing left ventricular diastolic and systolic function, calculated as [isovolumic contraction time + isovolumic relaxation time]/[left ventricular ejection time] (Tei index, shown as open squares in graph (c)) are shown.
They also showed increases in LV filling pressure (E/E' and E/Vp ratios), isovolumic relaxation time (IVRT), and myocardial performance index (Tei index of global cardiac function) (Table 1).
The measured steady-state hemodynamic parameters include derivative of pressure (dp/dtmax, dp/dtmin) and isovolumic relaxation constant (Tau).
The low impedance and the high capacitance of the normal pulmonary circulation are reflected in the triangular shape of the RV pressure-volume loop, without distinct periods of isovolumic contraction and relaxation [40-43].
The transmitral E and A waves velocities, E/A ratio, E wave deceleration time (DT), and the isovolumic relaxation time (IVRT) were measured using the conventional two dimensional and pulsed wave Doppler.
This value can be calculated by, dividing the sum of isovolumic contraction time and isovolumic relaxation time by the ejection time and extracting the LV ejection time from the time interval between the ending and the beginning of mitral flow for the LV and dividing it by the ejection time [15].
The results for right heart showed that Z scores for peak E velocity, peak A velocity, pre- ejection period, isovolumic relaxation time, myocardial performance index and isovolumic contraction time were significantly different (pless than 0.05).
Analysis of Left Ventricular Surface Deformation during Isovolumic Contraction.
The authors observed that in the subjects demonstrating an increase in Hbmass, isovolumic haemodilution elicited a 5.8% decrease in [VO.sub.2max].
Belova revealed the presence of diastolic dysfunction, later filling of the left ventricle and increased isovolumic relaxation period revealed in 120 young persons with LSBP [12].