922-54 Pericardial Thickness Measured by Transesophageal Echocardiography: Feasibility and Potential Clinical Utility

Abstract

Previous attempts to measure pericardial thickness (PT) using transthoracic echocardiography have yielded poor results. Transesophageal echocardiography (TEE), by virtue of enhanced image resolution should allow more reliable definition of the pericardium. Accordingly, we measured PT in 11 patients (mean age 53.1 yrs) with surgically proven constrictive pericarditis who underwent both TEE and electron beam computed tomogram (EBCT) ≤ 2 months apart. For comparison purposes, parietal PT was measured only in 4-chamber and basal short axis sections. Multiple measurements of PT were made independently by 2 observers (Obs) on digitized images to assess reliability and intra- and inter-observer variability. Twenty six measurements in different sites were made (mean 2.5/patient) yielding a mean PT of 5.7 mm (range 2.5 to 14.8 mm). EBCT measurements were made independently by a cardiac radiologist. Empty CellBland-Altman ± 2SD limits of agreement (mm)Empty CellCorrelation coefficient (r)Empty CellTEE Obs 1TEE Obs 2TEE Obs 1TEE Obs 2EBCT ± 1.6 ± 2.00.97*0.95*TEE Obs 1 ± 1.3 ± 0.90.98*0.99*TEE Obs 2 ± 0.9 ± 1.50.99*0.98**p < 0.0001 p < 0.0001 Significantly, there was reduced variability when mean PT was <5.5 mm (±2SD limits of agreement ± 0.8 and ± 1.0 mm for Obs 1 and 2 respectively). To further assess the ability of TEE to discriminate between thickened and normal pericardium, we measured PT in 20 normals (mean age 58.4 yrs). Normal PT was 1.2 ± 0.8 mm (Mean ± 2SD) and did not exceed 2.5 mm. A random series of 37 intraoperative TEEs (19 with thickened pericardium of whom 18 had constriction) was then reviewed by 2 blinded Obs. PT ≥ 3 mm on TEE differentiated thickened from from normal pericardium as follows (all data in %):Empty CellSensitivitySpecificity+Predictive accuracy-Predictive accuracyObs 31008990100Obs 489838588 TEE measurement of PT is feasible, reproducible and should be a valuable adjunct in the diagnosis of constrictive pericarditis.