[Determination of left atrial size. Comparison between echocardiographic and radiological determination].

The size of the left atrium was determined echocardiographically and radiologically in 66 patients with mitral valve disease, grade I-IV (New York Heart Association classification). Angiocardiography served as the reference. The echocardiographic determination was both by M-mode and two-dimensional, the radiological one was from the postero-anterior films (after Higgins), as well as from the lateral pictures. There was good agreement between the two echocardiographic methods and a good correlation of the two with cine-angiographic measurements (r = 0.82-0.99; P less than 0.001). But there was a poorer, although still statistically significant correlation of the radiologically determined atrial size with the echocardiographic and angiocardiographic measurements (r = 0.47-0.56; P less than 0.001). Thus M-mode and two-dimensional echocardiography is the more sensitive method for determining the size of the left atrium.