Visual Assessment of Left Ventricular Function in the Era of High Definition: The Machine and the Eye of the Beholder

Abstract

In the current era of sophisticated cardiac imaging, echocardiography is still a unique modality, in several ways. Beyond the obvious biomedical and logistic considerations, echocardiography is also unique because the acquisition and interpretation of images is critically dependent on the human factor, or at least more so compared with modalities that involve automated acquisition (computed tomography, magnetic resonance, radionuclide imaging). As such, echocardiography is bound to yield results with a wider margin of reproducibility compared with other cardiac imaging modalities. On the other hand, it is the very same human factor that renders echocardiography the most versatile imaging modality in clinical practice. In fact, a major advantage of echocardiography is the possibility for the rapid visual assessment of left ventricular wall motion abnormalities and global systolic function, an extremely useful tool in various clinical scenarios, and also heavily dependent on both the sonographer or the physician who acquires the images and the echocardiographer who interprets them. It is exactly this reliance on the human factor that has spurred multiple studies on the reproducibility of visual assessment of segmental and global left ventricular function. And although it is hard for echocardiography to claim victory in the reproducibility wars (at least in statistical terms), visual assessment has notably withstood the test of time. The question is whether visual assessment dominates clinical practice because the visual approach is clinically adequate or merely because inertia is innate to human nature.