Search results
Results from the WOW.Com Content Network
Flow-Volume loop showing successful FVC maneuver. Positive values represent expiration, negative values represent inspiration. At the start of the test both flow and volume are equal to zero (representing the volume in the spirometer rather than the lung). The trace moves clockwise for expiration followed by inspiration.
Pressure-Volume loops showing end-systolic pressure volume relationship. End-systolic pressure volume relationship (ESPVR) describes the maximal pressure that can be developed by the ventricle at any given LV volume. This implies that the PV loop cannot cross over the line defining ESPVR for any given contractile state.
Ventricular volume; Electrocardiogram; Arterial flow (optional) Heart sounds (optional) The Wiggers diagram clearly illustrates the coordinated variation of these values as the heart beats, assisting one in understanding the entire cardiac cycle. [1]
Very useful information can be derived by examination and analysis of individual loops or series of loops, for example: the horizontal distance between the top-left corner and the bottom-right corner of each loop is the stroke volume [5] the line joining the top-left corner of several loops is the contractile or inotropic state. [6]
For premium support please call: 800-290-4726 more ways to reach us
The minimum and maximum volumes (V max and V min) from each loop in the series of loops are plotted on a graph. V max and V min lines are extrapolated and at their point of intersection, where V max is equal to V min, must be zero—conductance is parallel conductance only. The volume at this point is the correction volume.
A flow that is not a function of time is called steady flow. Steady-state flow refers to the condition where the fluid properties at a point in the system do not change over time. Time dependent flow is known as unsteady (also called transient [8]). Whether a particular flow is steady or unsteady, can depend on the chosen frame of reference.
AOL latest headlines, entertainment, sports, articles for business, health and world news.