3.4 The left Atrium
The left atrium serves as a collecting reservoir of blood returning to the heart from the pulmonary veins. It plays an important role in the filling of the left ventricle. Many cardiac diseases affect the size and function of the heart. It is now a well established fact that the size of the left atrium is something like an imaging "biomarker". The size of the left atrium is a strong predictor of outcome in atrial fibrillation, stroke, heart failure and death. Therefore, measurements of the left atrium should be a major part of every echo exam.