Home‎ > ‎Left Ventricle‎ > ‎

4. LV Dimension & Shape


Normal LV has a conoid shape with a pointed apex: geometrical description of the LV is based on the assumption that its cavity represents a cylinder with a cone on the top (considering an apical TTE view) (figure 3A). Its walls are thicker than those of the right ventricle as the LV ejects its stroke volume into a high pressure circulation (figure 3B).

Figure 3. A TTE apical 4 chamber view shows normal LV shape; geometrical approximation as cylinder + cone is schematically depicted.   B. Anatomical specimens illustrate the difference in LV and RV wall thickness.

Adult LV is not capable of dilating acutely: any significant LV DILATATION is the marker of pre-existing LV dysfunction, as consequence of long-standing volume and/or pressure overload  (due to reduced contractility, left valves dysfunction, systemic hypertension, etc).

LV HYPERTROPHY, i.e. increased LV mass (mostly appreciated as increasd LV walls thickness)  requires time to develop: LV wall thickness increase is the consequence of long-standing pressure overload (Systemic Hypertension, Aortic Stenosis) or intrinsic myocardial disease (Hypertrophic Cardiomyopathy).

Significant LEFT ATRIAL ENLARGMENT is another marker of chronic LV dysfunction (as atria cannot significantly dilate acutely as well ): it derives from long standing volume/pressure overload.

QUALITATIVE ASSESSMENT OF LV DIMENSIONS

A qualitative assessment of LV dimensions of the LV can be done with simple “eyeballing” by a trained eye, keeping as reference the depth scale on the screen. This is what is usually required in focussed/“emergency” echocardiography (see FEEL & FATE modules).

Some examples of severe LV chronic dysfunction, self evident without performing any measure (look at centimeters on the depth scale) are given in TTE apical 4 chamber views of figure 4. By comparing with normal video clip and considering above mentioned concepts, guess the main LV morphological abnormalities and their potential cause (see answer in next page).

Figure 4. A to D: examples of chronic LV dysfunction. Estimate left heart dimensions looking at centimeters on the depth scale. Note also that depth is set to 18 cm for clip A, and to 20 cm for clips  B and D, to let the whole heart fit into the screen. (Clip D courtesy of Dr. Susanna Price)






























Schematic pictures corresponding to previously shown video clips illustrate main LV (and LA) structural changes in the context of different types of chronic heart disease (figure 5). Compare with previous page video clips.

Figure 5. A. Main feature is a markedly dilated LV (and LA), typical of Dilated Cardiomyopathy of potential Ischemic, Valvular, Idiopatic aetiology. B. An apical aneurism is evident as loss of pointed shape of LV apex with thin hyperecogenic wall C. Markedly hypertrophied LV with small cavity: is the consequence of Hypertrophic Cardiomyopathy (but can also be  found in longstanding untreated systemic hypertension, aortic stenosis). D. In this severe mitral stenosis, a small LV cavity is vice versa not associated with hypertrophic wall; a huge left atrium is also visible (video clip D, courtesy of Dr. Susanna Price).


Qualitative assessment of LV size is a function of interpreter skill and may have significant interobserver variability: beyond the practice of focussed/“emergency” Echo it should regularly be compared with quantitative measurements, especially when different views qualitatively suggest different degrees of LV abnormality.

Comments