QUANTIFICATION OF PERICARDIAL-EFFUSIONS BY 3-DIMENSIONAL ECHOCARDIOGRAPHY

Objectives. The purpose of this study was to examine the accuracy of three dimensional echocardiography for the quantification of asymmetric pericardial effusion volume and to compare this new technique with two-dimensional echocardiography. Background. Quantification of pericardial effusion by two- dimensional echocardiography relies on a symmetric distribution of the fluid. Three-dimensional echocardiography can quantitate volume without these limitations, but its accuracy for pericardial effusion volume has not yet been assessed. Methods. In six open chest dogs, 41 different asymmetrically distributed pericardial effusions of known volume were created by serial infusions of fluid through a pericardial catheter. The hearts were imaged using an automated echocardiographic method that integrates three-dimensional spatial and imaging data. The surfaces of the pericardial sac and heart were then reconstructed, and the volumes of pericardial effusions were calculated. Two-dimensional echocardiography was performed simultaneously, and volumes were calculated using the prolate ellipsoid method. Asymmetric distribution of the fluid was obtained by applying Localized hydrostatic pressure to the pericardium. Results. The volumes of pericardial effusion quantified using three dimensional echocardiography correlated well with actual volumes (y = 1.0x - 1.4, SEE = 7.7 ml, r = 0.98). Two-dimensional echocardiography had an acceptable correlation (y = 1.0x + 2.3, SEE = 23 ml, r = 0.84), but a marked degree of variation from the true value was observed for any individual measurement. Conclusions. Three dimensional echocardiography accurately quantifies pericardial effusion volume in vivo, even when the fluid is distributed asymmetrically, whereas two-dimensional echocardiography is less reliable. This new technique may be of clinical value in quantitating pericardial effusion, especially in the serial evaluation of asymmetric or loculated effusions.