Left ventricle size
From Echocardiography in ICU
With the measurement of the left ventricle diameter in diastole and in systole, you will be able to determine if the left ventricle is:
-dilated: mildly, moderately or severely
The left ventricle diameter is measured in parasternal long axis, at the tip of the mitral leaflets, at the interface blood-internall wall.
Left ventricle end-diastolic diameter: LVED, is the most important. It is measured at end diastole, on the frame after mitral closure. It normally corresponds to the largest cardiac dimension.
Left ventricle end-systolic diameter: LVES, is measured at end systole, on the frame preceding mitral valve opening. It corresponds to the smallest cardiac dimension.
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, otherwise you will overestimate the LV size.
Normal and abnormal values:
|LVED (mm)||Normal||Mildly dilated||Moderately dilated||Severely dilated|
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.
Shortening fraction = -------------------------- x 100