V1 showing the large negative of the P wave indicating<unk> <unk>  is suggested by an electrocardiogram (ECG) that has a pronounced notch in the P wave. However, if<unk>  fibrillation is present, a P wave would not be present. In any case,<unk>  can be diagnosed and measured using an echocardiogram (ECHO) by measuring the<unk><unk>  volume (LAVI). Characterizing the size of the<unk>  atrium according to its volume is preferred over a single linear dimension since enlargement can be different for different directions. For example, because of the smaller distance in the thoracic cavity between the sternum and spine, compared to the other directions, less room exists for enlargement of the<unk>  atrium along the anteroposterior axis. By approximating the shape of the<unk>  atrium as an ellipsoid, its volume can be calculated from measurements of its dimensions along three perpendicular directions. Indexing the<unk><unk>  volume to body surface area (volume/BSA) is recommended by the American Society of Echocardiography and the European Association of Echocardiography. The values for volume/BSA in the following table are the best validated, and are the same for both men and women.
Left atrial enlargement
Right atrial enlargement
Atrial enlargement
Aortic unfolding
Overriding aorta
Mitral facies
Mitral annular calcification
Left ventricular hypertrophy