Portions of left ventricle

The left ventricle may be subdivided into different portions:

• The base of the left ventricle is defined as the region adjacent to the mitral valve annulus, where the mitral valve leaflets are seen within the left ventricle. This is the most basal extent of the LV and is used for quantification in imaging and functional assessment. 

• The mid-ventricle refers to the portion of the LV where the papillary muscles are visualized, typically in the parasternal short-axis view in ultrasound; this region lies between the base and the apex.

• The apical part of the left ventricle is the segment distal to the papillary muscles, where the cavity tapers and no major internal structures are seen.

• The apex is the most distal tip of the left ventricle, anatomically thin, and located at the confluence of the terminus of the left anterior descending artery and the middle cardiac vein; it is used as a landmark for imaging and interventional procedures.

This subdivision is the base of the standardized 17-segment model for LV segmentation.