QUANTIFICATION OF PERICARDIAL-EFFUSIONS BY 3-DIMENSIONAL ECHOCARDIOGRAPHY

Objectives. The purpose of this study was to examine the accuracy of t hree dimensional echocardiography for the quantification of asymmetric pericardial effusion volume and to compare this new technique with tw o-dimensional echocardiography. Background. Quantification of pericard ial effusion by two- dimensional echocardiography relies on a symmetri c distribution of the fluid. Three-dimensional echocardiography can qu antitate volume without these limitations, but its accuracy for perica rdial effusion volume has not yet been assessed. Methods. In six open chest dogs, 41 different asymmetrically distributed pericardial effusi ons of known volume were created by serial infusions of fluid through a pericardial catheter. The hearts were imaged using an automated echo cardiographic method that integrates three-dimensional spatial and ima ging data. The surfaces of the pericardial sac and heart were then rec onstructed, and the volumes of pericardial effusions were calculated. Two-dimensional echocardiography was performed simultaneously, and vol umes were calculated using the prolate ellipsoid method. Asymmetric di stribution of the fluid was obtained by applying Localized hydrostatic pressure to the pericardium. Results. The volumes of pericardial effu sion quantified using three dimensional echocardiography correlated we ll with actual volumes (y = 1.0x - 1.4, SEE = 7.7 ml, r = 0.98). Two-d imensional 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 e ffusion volume in vivo, even when the fluid is distributed asymmetrica lly, whereas two-dimensional echocardiography is less reliable. This n ew technique may be of clinical value in quantitating pericardial effu sion, especially in the serial evaluation of asymmetric or loculated e ffusions.