Reporting of three-dimensional echocardiography-derived left ventricular volumes comes of age

Assessment of left ventricular function is the most requested indication for a transthoracic echocardiogram. This is because left ventricular volumes and ejection fractions play a crucial role, not only in managing, but also in predicting patient outcomes. Echocardiographic laboratories have made great strides in changing how left ventricular function is evaluated. There has been a movement from subjective qualitative reporting or 'eye-balling' to quantitative assessment, which provide volumes and calculated ejection fractions. More recently, the focus has been on improving echocardiographic volume measurements using three-dimensional transthoracic echocardiography. It has been well demonstrated that two-dimensional echocardiographic measurements of left ventricular volumes underestimate 'true' volumes compared with the reference standard of cardiac magnetic resonance imaging. This is because, with two-dimensional echocardiography, the imaging plane can be foreshortened and geometric assumptions are needed, as only the two- and four-chamber views are measured [1-3]. Regional wall motion abnormalities or aneurysms located in walls not seen in the two- and four-chamber views are not accounted for by these measurements. With three-dimensional echocardiography, a true volumetric assessment is performed, as all left ventricular wall segments are assessed. Multiple publications have demonstrated that three-dimensional echocardiography-derived left ventricular volumes and ejection fractions are more accurate and reproducible compared with cardiac magnetic resonance imaging [1,2,4]. This has led to guidelines supporting the clinical reporting of three-dimensional echocardiography-derived left ventricular volumes [5,6].