title: The diagnosis of pericardial effusion and cardiac tamponade by 12-lead ECG. A technology assessment.
abstract: OBJECTIVE
  This study was designed to determine the diagnostic value of 12-lead ECG for pericardial effusion and cardiac tamponade.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Hospitalized patients with and without pericardial effusion and cardiac tamponade.
  
  
  RESULTS
  In a blinded manner, we reviewed 12-lead ECGs from 136 patients with echocardiographically diagnosed pericardial effusions (12 of whom had cardiac tamponade) and from 19 control subjects without effusions. We examined the diagnostic value of three ECG signs: low voltage, PR segment depression, and electrical alternans. We found that all three ECG signs were specific but not sensitive for pericardial effusion (specificity, 89 to 100%; sensitivity, 1 to 17%) and cardiac tamponade (specificity, 86 to 99%; sensitivity, 0 to 42%). None of the ECG signs were associated with pericardial effusions of all sizes, but low voltage was associated with large and moderate pericardial effusions (odds ratio = 2.5; 95% confidence interval [CI] = 0.9 to 6.5; p = 0.06) and with cardiac tamponade (odds ratio = 4.7; 95% CI = 1.1 to 21.0; p = 0.004). In contrast, PR segment depression was associated only with cardiac tamponade (odds ratio = 2.0; 95% CI = 1.0 to 4.0; p = 0.05), while electrical alternans was not associated with either pericardial effusion or cardiac tamponade.
  
  
  CONCLUSIONS
  Low voltage and PR segment depression are ECG signs that are suggestive, but not diagnostic, of pericardial effusion and cardiac tamponade. Because these ECG findings cannot reliably identify these conditions, we conclude that 12-lead ECG is poorly diagnostic of pericardial effusion and cardiac tamponade.
authors.affiliation: Department of Medicine, University of California, San Francisco 94143, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Eisenberg
authors.forename: L M
authors.initials: LM
authors.lastname: de Romeral
authors.forename: P A
authors.initials: PA
authors.lastname: Heidenreich
authors.forename: N B
authors.initials: NB
authors.lastname: Schiller
authors.forename: G T
authors.initials: GT
authors.lastname: Evans
mesh_terms: D002305:Cardiac Tamponade / Q000175:diagnosis* / Q000000981:diagnostic imaging; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D004452:Echocardiography; D004562:Electrocardiography; D006801:Humans; D008297:Male; D008875:Middle Aged; D010490:Pericardial Effusion / Q000175:diagnosis* / Q000000981:diagnostic imaging; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity