title: The anteroposterior pericardial sac diameter measured by echocardiography correlates with the volume of pericardial effusion and with effort dyspnea.
abstract: OBJECTIVE
  To examine the value of the anteroposterior pericardial sac diameter (APD) for prediction of the volume of pericardial effusion.
  
  
  RESULTS
  We measured the APD by echocardiography before 52 pericardiocentesis procedures and correlated it with the aspirate volume, etiology, symptoms, and clinical outcome. The volume of the aspirate ranged from 60 to 2300 ml (median 650 ml). The APD (range 8.0 cm-15.9 cm, median 12 cm) correlated well with the cubic root of the volume of the effusion [volume=(0.8APD-0.6)3, r2=0.533, p<0.01]. An APD>or=12 cm had a positive predictive value of 88% and a negative predictive value of 83% for effusion volume above the sample median (>or=650 ml) and a positive predictive value of 100% for effusion in the middle or upper aspirate volume tertiles. Effort dyspnea was more common among patients with APD>or=12.0 cm (n=13) than in those with APD<12.0 cm (n=11) (p=0.007). One-year survival after pericardiocentesis was closely related to the severity of the underlying etiology and was not influenced by the volume of the effusion before aspiration.
  
  
  CONCLUSIONS
  The APD is a simple, valuable method for non-invasive prediction of pericardial fluid volume. A greater APD is associated with, and may explain, effort dyspnea.
authors.affiliation: Department of Cardiology, Rabin Medical Center-Beilinson Campus, Petah Tiqva, and Sackler Faculty of Medicine, Tel Aviv University, Israel. avivm@clalit.org.il
authors.forename: Aviv
authors.initials: A
authors.lastname: Mager
authors.forename: Yochai
authors.initials: Y
authors.lastname: Birnbaum
authors.forename: Yehuda
authors.initials: Y
authors.lastname: Adler
authors.forename: Shula
authors.initials: S
authors.lastname: Imbar
authors.forename: Boris
authors.initials: B
authors.lastname: Strasberg
authors.forename: Alexander
authors.initials: A
authors.lastname: Battler
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002305:Cardiac Tamponade / Q000000981:diagnostic imaging; D004417:Dyspnea / Q000000981:diagnostic imaging* / Q000473:pathology; D004452:Echocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010490:Pericardial Effusion / Q000000981:diagnostic imaging* / Q000473:pathology; D020519:Pericardiocentesis; D010496:Pericardium / Q000000981:diagnostic imaging* / Q000473:pathology*; D011237:Predictive Value of Tests; D016019:Survival Analysis; D016896:Treatment Outcome