Left ventricle size

From Echocardiography in ICU

(Difference between revisions)
Jump to: navigation, search
 
Line 13: Line 13:
<br>
<br>
-
<br>
+
<br><wikiflv repeat="true" autostart="true" width="480" height="341">Normal_echo_PSL.flv</wikiflv>  
=== <span style="color: #cc0000"><u>Diastolic diameter</u></span>  ===
=== <span style="color: #cc0000"><u>Diastolic diameter</u></span>  ===
Line 21: Line 21:
<br>
<br>
-
[[Image:LVED measurement.jpg|center|320px]]  
+
[[Image:LVED measurement.jpg|center|480px]]  
<br>
<br>
Line 33: Line 33:
<br>
<br>
-
[[Image:LVES measurement.jpg|center|320px]]  
+
[[Image:LVES measurement.jpg|center|480px]]  
<br>
<br>
Line 43: Line 43:
The LV dimensions can be measured in M-mode. This imaging modality allows the visualization of each structure depending on the time and gives a better image resolution than 2D imaging. However you must be sure that the imaging beam is cutting perpendicularly the long axis of the left ventricle or you will overestimate the LV size.  
The LV dimensions can be measured in M-mode. This imaging modality allows the visualization of each structure depending on the time and gives a better image resolution than 2D imaging. However you must be sure that the imaging beam is cutting perpendicularly the long axis of the left ventricle or you will overestimate the LV size.  
-
[[Image:LV measurement Mmode.jpg|center|320px]]  
+
[[Image:LV measurement Mmode.jpg|center|480px]]  
<br>
<br>
Line 76: Line 76:
=== <br><br><span style="color: #cc0000"><u>Pitfalls of LV diameter measurement</u> </span> ===
=== <br><br><span style="color: #cc0000"><u>Pitfalls of LV diameter measurement</u> </span> ===
-
&nbsp;
+
&nbsp;  
*Be careful to exclude the chordae and papillary muscle from the measurement  
*Be careful to exclude the chordae and papillary muscle from the measurement  

Latest revision as of 14:10, 23 June 2009

The objective of this chapter is to determine if the left ventricle is:    

-small

-dilated: mildly, moderately or severely

-normal size


The left ventricle diameter is measured in parasternal long axis, at the tip of the mitral leaflets, at the interface blood-internall wall.



Contents

Diastolic diameter

LVED: left ventricle end-diastolic diameter, is the most important measurement. It is measured at end diastole, on the frame after mitral closure. It normally corresponds to the largest cardiac dimension.


LVED measurement.jpg



Systolic diameter

LVES: left ventricle end-systolic diameter, is measured at end systole, on the frame preceding mitral valve opening. It corresponds to the smallest cardiac dimension.


LVES measurement.jpg



M-mode measurements

The LV dimensions can be measured in M-mode. This imaging modality allows the visualization of each structure depending on the time and gives a better image resolution than 2D imaging. However you must be sure that the imaging beam is cutting perpendicularly the long axis of the left ventricle or you will overestimate the LV size.

LV measurement Mmode.jpg



Normal and abnormal values

LVED (mm) Normal Mildly dilated Moderately dilated Severely dilated
Men 42-59 60-63 64-68 >69
Women 39-53 54-57 58-61 >62




Pitfalls of LV diameter measurement

 

  • Be careful to exclude the chordae and papillary muscle from the measurement
  • Measure perpendicularly to the long axis of the left ventricle
  • Your PSL view must be parallel to the long axis of the LV: the septum and posterior wall should be parallel, and you should not visualize the LV apex



Left ventricle shortening fraction


With the left ventricle end-diastolic and end-systolic diameters, you will be able to calculate the shortening fraction. The shortening fraction reflects the left ventricle systolic function, but is valid only if the left ventricle geometry is normal and in the absence of wall motion abnormality.


                                    (LVED-LVES)

Shortening fraction = -------------------------- x 100

                                         LVED



                             

Shortening fraction  %
Normal 25-45
Mild 20-25
Moderate 15-20
Severe <15
Personal tools