Quantifying Pericardial Fat Volume

Pericardial fat was measured using noncontrast coronary artery calcium scans acquired using electron beam computed tomography (GE-Imatron C-150; GE-Imatron, San Francisco, California). The methods by which pericardial fat was assessed have been described previously (40 (link)). Forty contiguous 3-mm slices were taken during a single breath-hold starting at the carina and proceeding to the level of the diaphragm. Scan time was 100 ms/slice, synchronized to 40% of the R-R interval. Two experienced investigators blinded to any psychophysiological and clinical data calculated the volume of pericardial fat (in cubic centimeters) on a Siemens multimodality workstation (Siemens, Forchheim, Germany). For the present study, we adjusted pericardial fat volume for body surface area using the formula derived by Dubois and Dubois (body surface area (m²) = weight (kg)^0.425 × height (cm)^0.725 × 0.007184) (41 (link)) to correct for differences in heart size (giving values in cubic centimeters per meter squared) (42 (link)).