Quantitative Echocardiographic Assessment in Pericardial Disease

Although echocardiography has been used for diagnosing pericardial effusions since 1965, the grading of such effusions for size, and also the diagnosis of tamponade have depended almost entirely on qualitative observations or "signs." The categorization of pericardial effusions into small, moderate, or large according to the width of pericardial space is very roughly semiquantitative. Diagnostic criteria for tamponade are based on altered ventricular or atrial wall contour, and on phasic respiratory fluctuations of ventricular size and flow velocities. We review a new approach to pericardial effusion volume estimation, based on assessing the pericardial sac volume as well as cardiac volume by the ellipsoid formula. A new quantitative criteria for tamponade (i.e., biatrial width to cardiac width) (annular level) ratio may be useful, a ratio < 0.85 indicating tamponade, reflecting late diastolic biatrial collapse. The echo diagnosis of pericardial constriction depends on pericardial thickening combined with various abnormalities of septal and ventricular wall motion, some of them subtle. We review a new two-dimensional echo "sign" present in some cases of pericardial constriction: abnormal posterior displacement of the left atrial posterior wall, and reduced angle (<150 degrees ) between it and left ventricular wall in long-axis view. Measurements reflecting the fluctuation of certain Doppler parameters can also be useful in diagnosis of this entity.