[Echocardiographic evaluation of left atrial function in dilated cardiomyopathy with restricted and non-restricted Doppler transmitral flow]

Abstract

Left atrial (LA) function is of great importance in left ventricular (LV) filling. There is evidence that echocardiographic Doppler evaluation of transmitral flow, routinely used for LV filling estimation, is dependent on LA function. Information regarding the relation of LA size and function to transmitral flow in heart failure is limited. We used 2D echocardiographic acoustic quantification methods to assess LA function in patients with dilated, (non-ischemic) cardiomyopathy (DCM) and a control group. The DCM group was divided into 2 subgroups: Group 1-with restrictive LV Doppler filling pattern-18 patients (DCM-R) and Group 2-with non-restrictive LV Doppler filling pattern-11 patients (DCM-NR) with similar heart rate, age and degree of mitral regurgitation. LA maximal area, total emptying fraction and absolute and fractional area change during rapid emptying and atrial contraction were calculated. The LA was enlarged only in DCM-R. Both DCM groups had decreased total emptying fractions and rapid emptying area changes compared to controls. An enlarged LA area and more decreased total emptying were found in DCM-R with high LV filling pressures compared to DCM-NR. The restrictive group had a significantly smaller LA rapid emptying area change, as well as a smaller LA area change and emptying fraction during atrial contraction compared to DCM-NR. Within < or = 2 hrs after the echocardiography study, cardiac catheterization was performed in the DCM group. We found significantly higher LV filling pressures and lower LV ejection fractions in DCM-R compared to DCM-NR. Significant correlations were found between LA function and invasive parameters like capillary wedge and LV enddiastolic pressures and LV EF.

Conclusion: Patients with DCM-R had significantly enlarged LA areas with more depressed total emptying fractions and smaller LA area changes during contraction compared to DCM-NR. Thus, left atrial function plays an important role in LV filling and its dysfunction can be a marker of poor prognosis.