Switching to volumetric left atrial measurements: impact on routine echocardiographic practice

To define the change in the prevalence of reported left atrial enlargement (LAE) brought by using volumetric rather than linear measurements and to detect whether individuals with LAE that would have been missed by linear measurements represent a distinct subgroup of patients.

Left atrial (LA) linear dimensions and volumes were obtained and correlated with clinical and echocardiographical variables in 168 consecutive patients (age: 69 ± 10 years) undergoing routine echocardiographic studies. LAE was diagnosed in 109 out of 168 patients (65%) by volume criteria as opposed to 68 out of 168 patients (40%) by linear dimension criteria, resulting in a 'missing rate' of 37% for the latter. Patients with LAE diagnosed by volume but not by diameter measurements had a lower left ventricular mass index (LVMI).

Adopting volume measurements for the LA may result in almost 40% increase in the number of patients reported as having LAE. The lower LVMI found in these patients suggests that volume-based measurements are more sensitive and detect LAE at an earlier stage than diameter-based measurements, although the prognostic and management impact of this finding remains to be established.