Two-Dimensional Echocardiographic Quantitation of Left Ventricular Global and Regional Shape: Validation of an Algorithm Based on Fourier Transformation and Curvature Measurements of Endocardial Contours.

Left ventricular geometry is an important parameter of its function; however, left ventricular function has been conventionally quantified through measurements of volume, ejection fraction, and mass. Left ventricular global shape has been quantified previously using methods that are based on assumptions of idealized cavity shape. Although these indices have been applied to various disease states of the left ventricle, the underlying assumption of an ideal left ventricular geometry is inherently flawed. Regional left ventricular shape using echocardiography has not been previously evaluated, principally because of the difficulty in quantitative regional geometry. Alterations in left ventricular geometry have a direct impact on wall stress and thus the diastolic performance of the left ventricle. We developed an algorithm based on Fourier transformation of traced endocardial borders from two-dimensional echocardiograms that allowed global shape of the left ventricular to be quantified without assumptions of any ideal left ventricular shape. This method is an adaptation of an algorithm defined for cineventriculograms by Marino and colleagues (Am J Physiol 1988;254:H547-H557). We further described a method to quantify regional endocardial curvature as an index of regional shape. In this preliminary validation study, we primarily tested the reproducibility of these two parameters.