ABSTRACT
Left atrial (LA) geometry varies and is not accurately represented by a linear dimension. Left atrial size needs to be assessed more accurately if:
atrial diameter >40 mm in the parasternal long-axis view
hypertension (as a sign of chronically increased filling pressure)
atrial fibrillation (likely success of cardioversion, thromboembolic risk)
mitral valve disease (thromboembolic risk, indirect marker of severity)
suspected LV diastolic heart failure.