Assessment of left ventricular filling pressures by Doppler in the presence of atrial fibrillation

BACKGROUND

Although Doppler echocardiography can be used to estimate left ventricular filling pressures (LVFPs) in patients in sinus rhythm, its utility in atrial fibrillation is unknown.

METHODS AND RESULTS

An initial training population of 30 patients (17 men, 13 women: mean age, 69 +/- 9 years; range, 48 to 87 years) was studied. Measurements of LVFP were obtained simultaneously with pulsed Doppler recordings of mitral and pulmonary venous flow velocities and color M-mode recording of the flow propagation velocity of the mitral inflow. Measurements were averaged over 10 cardiac cycles. In addition, left atrial volume was derived from the apical four-chamber view. Significant relations were observed between LVFP and several parameters derived from the transmitral and pulmonary venous velocity and left atrial volume. The best relations were observed with the peak acceleration (PkAcc) of the mitral velocity (r = .84), isovolumic relaxation time (IVRT) (r = .76), mean early (E) velocity (r = .6), and the ratio of peak E velocity to color M-mode flow propagation velocity (r = .65). The best model obtained by multilinear regression analysis (r = .88) included PkAcc and IVRT. The equation LVFP = 22+0.005 (PkAcc)-0.183(IVRT) was tested in 30 additional patients (12 women and 18 men: mean age, 65 +/- 10.6 years; range, 43 to 87 years) with similar results (r = .87). When all 60 patients were combined, the mean +/- ISD difference between predicted and observed pressure was -0.88 +/- 3.6 mm Hg.

CONCLUSIONS

LVFPs can be estimated with Doppler echocardiography in patients with atrial fibrillation.

Relation of mean right atrial pressure to echocardiographic and Doppler parameters of right atrial and right ventricular function

BACKGROUND

A paucity of data exists as to the relation of mean right atrial pressure (RAP) to Doppler parameters of right atrial and ventricular filling. Furthermore, whether echocardiographic parameters of right atrial and right ventricular function and inferior vena cava improve the relation of Doppler filling dynamics with RAP has not been explored.

METHODS AND RESULTS

Doppler and echocardiographic studies were performed simultaneously with measurements of mean RAP in consecutive patients who either had a central venous catheter in the Intensive Care Unit or underwent catheterization of the right side of the heart. The initial population consisted of 35 patients with a mean age (+/-SD) of 60+/-15 years; 34% were on mechanical ventilation. Mean RAP averaged 9+/-5.7 mm Hg (range, 2 to 28 mm Hg). Among tricuspid inflow parameters, the strongest relation with RAP was observed with the ratio of early to late velocity (r=.66). For hepatic venous flow, systolic filling wave indexes had the best relation with atrial pressure, the highest being for systolic filling fraction (r=-.86). Weaker relations were noted with the use of right atrial volumes, right ventricular function, and inferior vena caval diameters. The addition of any of these variables did not improve the relation of systolic filling fraction with RAP. The regression equation (RAP=21.6-24 systolic filling fraction) was tested prospectively in the estimation of atrial pressure 50 patients. The correlation coefficient was .89 in the prospective group and .88 in the total group of 85 patients. The mean difference between predicted and actual pressures in the whole population was -0.2+/-2.6 mm Hg. The sensitivity and specificity for mean RAP>8 mm Hg were 86% and 92%, respectively.

CONCLUSIONS

Among echocardiographic and Doppler parameters of right atrial and right ventricular function, hepatic venous flow dynamics relate best to mean atrial pressure and can be used clinically to estimate mean RAP.

Feasibility and accuracy of Doppler echocardiographic estimation of pulmonary artery occlusive pressure in the intensive care unit

Mitral inflow and pulmonary vein inflow variables have been shown to relate to left ventricular filling pressures. However, the feasibility and accuracy of Doppler estimation of pulmonary artery (PA) occlusive pressure in the intensive care unit have not been previously assessed. Accordingly, 67 consecutive patients in intensive care units who had PA catheters underwent Doppler recordings of mitral inflow, pulmonary vein flow, and isovolumic relaxation time (IVRT). Thirty-six patients met Doppler inclusion criteria. Most exclusions were due to atrial fibrillation, merging of peak velocity during early diastole (E) and atrial contraction (A) mitral flow velocities, and inadequate recordings. Mean age (+/- SD) was 65 +/- 12 years, ejection fraction varied between 19% and 80%, and 45% of patients were on mechanical ventilation. Doppler-derived variables were related to occlusive pressure (mean 16 +/- 6 mm Hg, range 6 to 40), and the most significant variables were entered into a multiple linear regression analysis. The derived relation was tested in 30 repeat studies after a variety of hemodynamic interventions and in a prospective group of 32 additional patients (mean age 63 +/- 11.6 years, pressure range 7 to 28 mm Hg). The highest correlations with occlusive pressure were observed with the E/A ratio (r = 0.75), IVRT (r = -0.55), atrial filling fraction (r = -0.65), and deceleration time (r = -0.50). Pulmonary venous recording could be obtained in only 16% of patients. The best model was with E/A and IVRT: PA occlusive pressure = 17 + (5.3 E/A)-(0.11 IVRT), r = 0.79.(ABSTRACT TRUNCATED AT 250 WORDS)