Left atrium (LA) may serve as a conduit, as a reservoir and as a contractile chamber. Left atrial function in patients with left ventricular concentric hypertrophy was compared with that in eccentric hypertrophy.

LA volumes were echocardiographically measured in 54 hypertensive patients (mean age: 57.1±14.9 years, men: 24, women: 30, concentric hypertrophy: 21, eccentric hypertrophy: 18). Transmitral flow velocities were recorded with pulsed Doppler echocardiography. LA volumes were measured at mitral valve opening (LAVmax) and closure (LAVmin) and at onset of atrial systole (LAVp). LA function was evaluated by the following parameters: 1) LA reservoir volume (LARV=LAVmax-LAVmin), 2) LA conduit volume (LACV=left ventricular stroke volume-LARV), 3) LA active emptying fraction (EF active=[LAVp-LAVmin]/LAVp), 4) LA passive emptying fraction (EF passive=[LAVmax-LAVp]/LAVmax).

In concentric hypertrophy compared with eccentric hypertrophy, LARV (59.9±20.0 vs 45.6±12.0 cm3, p<0.05) and EF active (56.8±10.0 vs 41.0±15.2%, p<0.01) increased but LACV (16.0±19.8 vs 43.7±15.0 cm3, p<0.01) decreased. Relative wall thickness (RWT) correlated with LARV (r=0.288, p<0.05) and EF active (r=0.561, p<0.01) but had negative association with LACV (r=-0.508, p<0.01) and EF passive (r=-0.490, p<0.01). There was a positive relationship of left ventricular mass index (LVMI) to LARV (r=0.293, p<0.05) but negative relationship of LVMI to EF passive (r=-0.494, p<0.01).

The present study showed that LA reservoir function and active emptying fraction increased in concentric hypertrophy comparison with eccentric hypertrophy and LA conduit function decreased in concentric hypertrophy comparison with eccentric hypertrophy. Therefore, these findings suggest that the changes of left atrial function are remarkable in concentric hypertrophy.