title: The relationship between left and right pericardial pressures in humans: an intraoperative study.
abstract: BACKGROUND
  The purpose of this study was to show the similarity between the pericardial constraint over the right and left ventricles of humans at various levels of central venous pressure (CVP) using flat Silastic balloons in the pericardial space during elective cardiac surgery.
  
  
  METHODS
  Six subjects (aged 19-76 years) were instrumented with flat, liquid-containing Silastic balloons in the pericardial space during elective cardiac surgery. No subject had valvular disease or right ventricular (RV) hypertrophy. These balloons were positioned to lie over the RV and left ventricular (LV) free walls to measure RV and LV pericardial pressure (P(prv) and P(plv), respectively). Volume loading was achieved by an intravenous infusion of 1 to 2 L of Ringer's lactate or normal saline. Depending on the patient's status during the operative procedure, the mean CVP was increased by 5-10 mm Hg from the baseline postinduction levels. RV and LV pericardial pressures were measured continuously throughout the volume loading.
  
  
  RESULTS
  The pooled data from all subjects demonstrate that RV pericardial pressure is equal to LV pericardial pressure over central venous pressures ranging from 4 to 18 mm Hg and that the RV late-diastolic (pre-a-wave) cavitary pressure (P(rv)) correlates with LV pericardial pressure.
  
  
  CONCLUSIONS
  Changes in LV pericardial pressure are approximately equal to changes in RV pericardial pressure and RV late-diastolic (pre-a-wave) cavitary pressure is a good predictor of LV pericardial pressure.
authors: Department of Family and Community Medicine, Baylor College of Medicine, Texas Medical Center, Houston, Texas, USA. jtyberg@ucalgary.ca
authors: Douglas R
authors: DR
authors: Hamilton
authors: Rozsa
authors: R
authors: Sas
authors: Roy A
authors: RA
authors: Semlacher
authors: Teresa M
authors: TM
authors: Kieser Prieur
authors: John V
authors: JV
authors: Tyberg