Left atrial volume predicts abnormal exercise left ventricular filling pressure

Latent heart failure at rest can be observed in a number of patients upon exercise. Considering left atrial (LA) remodelling as the reflection of the cumulative effects of the LV filling pressure (FP) over time, our aim was to investigate whether the LA volume would predict abnormal exercise LVFP.

Ninety patients (58.6 ± 10.8 years, 74 men) underwent exercise echocardiography. The LA maximal volume was measured by the Simpson method and indexed to body surface area. LVFP was assessed by the ratio between early peak diastolic velocities of mitral inflow and the septal annular mitral plane (E/e'). Exercise E/e' >13 was used as a threshold to define abnormal LVFP. Indexed LA volume was correlated with E/e' at rest (r = 0.37, P = 0.003), but the correlation was better with exercise E/e' (r = 0.54, P < 0.0001). In multivariate analysis, age, LV end-diastolic volume index, LVEF, and exercise E/e' were the independent determinants of LA volume index (R(2)  = 0.47, P < 0.0001). Eleven patients had exercise E/e' >13; compared with the rest of the population, these patients were older and achieved a milder effort. LA volume index >33 mL/m(2) predicted an abnormal exercise LVFP with a 91% sensitivity and a 78% specificity. None of the patients with an LA volume index <26 mL/m(2) (n = 31, 34%) had an exercise E/e' >13.

Exercise LVFP is a determinant of LA size. LA volume index seems to be helpful for predicting abnormal exercise LVFP. The potential use of LA remodelling to identify the patients benefitting most from exercise echocardiography should be investigated in larger studies.