title: Non-invasive estimation of right atrial pressure by combined Doppler echocardiographic measurements of the inferior vena cava in patients with congestive heart failure.
abstract: BACKGROUND
  In patients with congestive heart failure, evaluation of right atrial pressure (RAP) provides useful therapeutic, functional and prognostic information. The aim of this study was to investigate whether a combination of inferior vena cava variables measured by Doppler echocardiography could provide a reliable non-invasive estimate of RAP.
  
  
  METHODS
  One hundred consecutive patients with severe congestive heart failure (ejection fraction 24 +/- 6%) due to dilated cardiomyopathy were evaluated by simultaneous Doppler echocardiography and hemodynamic studies. RAP, end-expiratory (IVCDmax) and end-inspiratory (IVCDmin) diameters of the inferior vena cava, its collapse index [CIIVC = (IVCDmax - IVCDmin/IVCDmax)*100] and systolic fraction of forward inferior vena cava flow were measured and correlated by both single and multilinear regression analysis. The accuracy of generated equations was tested in a separate testing group of 61 patients at baseline and a subgroup of 20 patients after loading manipulations, prospectively studied in the same methodological setting.
  
  
  RESULTS
  All Doppler echocardiographic variables were correlated with RAP. The IVCDmin showed the strongest correlation (r = 0.84, p < 0.0001). Stepwise regression analysis identified two equations for predicting RAP: 1) RAP = (6.4*IVCDmin + 0.04*CIIVC - 2) (r = 0.82, p < 0.0001, SEE 1.7 mmHg) in all patients, and 2) RAP = (4.9*IVCDmin + 0.01*CIIVC - 0.2) (r = 0.92, p < 0.0001, SEE 1.2 mmHg) in patients without tricuspid regurgitation. In the testing group estimated and measured RAP was strongly correlated at baseline (r = 0.95, SEE 1.3 mmHg, p < 0.00001) and after loading manipulations (r = 0.96, SEE 1.2 mmHg, p < 0.00001). The agreement between invasive and non-invasive measurements of RAP in identifying patients with normal (< or = 5 mmHg), moderately increased (< 5 RAP < 10 mmHg) and markedly increased (> or = 10 mmHg) RAP was 81 or 93% using equation 1 or 2, respectively.
  
  
  CONCLUSIONS
  Our results provide evidence that in patients with congestive heart failure indices derived from Doppler measurements of the inferior vena cava can be used to produce an accurate, strong and non-invasive estimate of RAP. This is another example of the usefulness of Doppler echocardiography in evaluating hemodynamic profile and its changes in patients with congestive heart failure. Echocardiographic assessment of the inferior vena cava should be included in the evaluation of patients with congestive heart failure.
authors.affiliation: Fondazione Salvatore Maugeri, Clinica del Lavoro e della Riabilitazione, IRCCS, Istituto Scientifico Montescano, Divisione di Cardiologia, Montescano, PV, Italy. scapomolla@fsm.it
authors.forename: S
authors.initials: S
authors.lastname: Capomolla
authors.forename: O
authors.initials: O
authors.lastname: Febo
authors.forename: A
authors.initials: A
authors.lastname: Caporotondi
authors.forename: G
authors.initials: G
authors.lastname: Guazzotti
authors.forename: M
authors.initials: M
authors.lastname: Gnemmi
authors.forename: A
authors.initials: A
authors.lastname: Rossi
authors.forename: G
authors.initials: G
authors.lastname: Pinna
authors.forename: R
authors.initials: R
authors.lastname: Maestri
authors.forename: F
authors.initials: F
authors.lastname: Cobelli
mesh_terms: D000704:Analysis of Variance; D016280:Atrial Function, Right / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D006328:Cardiac Catheterization; D015150:Echocardiography, Doppler; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D016014:Linear Models; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D012119:Respiration; D014262:Tricuspid Valve Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology; D014682:Vena Cava, Inferior / Q000000981:diagnostic imaging / Q000502:physiology*