Usefulness of left atrial volume for the differentiation of normal from pseudonormal diastolic function pattern in patients on hemodialysis.

BACKGROUND

Discrimination of normal from pseudonormal mitral flow is challenging in clinical practice, especially in a milieu of acute plasma volume changes, such as in patients undergoing hemodialysis (HD). Left atrium (LA) enlargement has been recognized as a marker of the duration of left ventricular diastolic dysfunction. We hypothesize that LA volume index (LAVi) may be useful to differentiate normal from pseudonormal left ventricular filling pattern in this scenario.

METHODS

Fifty clinically stable patients undergoing HD (of 138 evaluated in a routine examination) in sinus rhythm who had an early to atrial transmitral velocity ratio between 1 and 2 on Doppler echocardiography were selected and divided into normal (n = 28) and pseudonormal (n = 22) groups based on mitral annulus tissue Doppler and pulmonary venous flow data. Receiver operating characteristic curves for LAVi and other echocardiographic parameters were generated to compare the discriminating power between normal and pseudonormal mitral flow.

RESULTS

The mean LAVi for patients with normal mitral flow was 24 +/- 6 versus 48 +/- 16 mL/m(2) in those with pseudonormalization (P < .001). LAVi had the best overall performance in comparison with several echocardiographic parameters (area under the curve 0.94, 95% confidence interval 0.84-1.0, P < .001). LAVi greater than 35 mL/m(2) was 91% sensitive and 89% specific for the detection of pseudonormalization in patients undergoing HD.

CONCLUSION

Enlargement of LA reflects the chronicity and burden of left ventricular diastolic dysfunction in stable patients undergoing HD with early to atrial transmitral velocity ratio apparently normal on conventional Doppler echocardiography. LAVi is a practical and useful parameter to discriminate normal from pseudonormal mitral flow.