Clinical physiology and functional imaging
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Clin Physiol Funct Imaging · Sep 2015
Comparative Study Clinical TrialRelationship between pulse pressure variation and echocardiographic indices of left ventricular filling pressure in critically ill patients.
Pulse pressure variation (PPV) is a dynamic index of fluid responsiveness. This parameter helps clinicians in improving haemodynamic status while avoiding potential fluid overload. Echocardiographic indices, such as E/E' ratio and left atrial (LA) strain by speckle tracking echocardiography (STE), are used to estimate left ventricular (LV) filling pressures. This study aimed at exploring the relationship between PPV and echocardiographic indices of LV filling pressures in critically ill patients. ⋯ In a group of mechanically ventilated patients PPV, derived from pulse contour analysis, and echocardiographic preload parameters were well correlated. Global PALS by STE provided better estimation of PPV than mean E/E' ratio. PALS seems a potential alternative to PPV in assessing fluid responsiveness in critically ill patients.
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Clin Physiol Funct Imaging · Sep 2015
Local architecture of the vastus intermedius is a better predictor of knee extension force than that of the other quadriceps femoris muscle heads.
The purpose of this study was to determine whether the muscle architecture of each head of the quadriceps femoris (QF) at multiple regions can be used to predict knee extension force. Muscle thickness and pennation angle were measured using sonographic images from multiple regions on each muscle of the QF with the knee flexed to 90°. The fascicle lengths of the rectus femoris (RF), vastus lateralis (VL) and vastus intermedius (VI) muscles were estimated based on sonographic images taken along the length of the thigh. ⋯ The muscle thickness of the ant-VI was selected as an independent variable in the first step of the linear regression analysis (R(2) = 0.66, P<0.01). In the second step, pennation angle of the lat-VI was added to the model (R(2) = 0.91, P<0.01). These results suggest that among the four muscles that make up the QF, the muscle architecture of the VI is the best predictor of knee extension force.