Left atrial size and force in patients with systolic chronic heart failure: Comparison with healthy controls and different cardiac diseases.

backgroundLeft atrial (LA) systolic force (LASF) is significantly increased in chronic heart failure (CHF), arterial hypertension (HT) and aortic stenosis (AS). The increase is proportional to the degree of left ventricular hypertrophy and diastolic dysfunction.

objectivesTo assess the magnitude of changes in maximal LA volume (LAV(max)) and LASF in systolic CHF compared with other cardiac diseases, and to assess whether the left atrium remodels differently and works in response to specific conditions affecting diastolic function and to individual factors associated with LA alterations.

methodsLAV(max) and LASF were measured and evaluated by two-dimensional Doppler echocardiography in 94 patients with systolic CHF and normal left ventricular filling pressure, 100 control patients, 181 patients with HT, 40 patients with idiopathic hypertrophic cardiomyopathy (HCMP) and 85 patients with AS. The prevalence of LA dilation and supernormal LASF (defined as values of LAV(max) and LASF exceeding two SDs of the mean of controls) was measured in all groups.

resultsLAV(max) and LASF were 7.1±2 mL/m(3) and 7.8±4 kdynes in controls, and 11.0±4 mL/m(3) and 19.7±11 kdynes in systolic CHF patients, respectively (both P<0.001). These values were significantly higher than in patients with HT, but similar to those with AS and HCMP. LA dilation and supernormal LASF were detected in 13% and 11% of patients with HT, 32% and 59% of patients with AS, 26% and 43% of patients with HCMP, and 41% and 56% of patients with systolic CHF, respectively (all P<0.01). In multiple logistic analysis, systolic CHF represented the strongest predictor of supernormal LASF. It was not independently associated with LA dilation, which was mainly related to indexes of volume load.

conclusionsLAV(max) and LASF were markedly increased in patients with systolic CHF, with a magnitude that was significantly higher than that of HT patients, but similar to that measured in HCMP and AS patients. In the present community population with various cardiac diseases, systolic CHF represented the most powerful stimulus for increasing LASF and was not related to LA dilation.