Left atrial enlargement is a diagnosis made when the left atrium of a person's heart is larger than normal. The Ochsner Journal explains that left atrial size is measured through echocardiography. The recommended way to determine the size of the left atrium is to measure its volume. Although linear dimensions may also be measured, this method is less accurate.
The size of a person's left atrium is influenced by the presence of obesity and high blood pressure, according to Medical News Today. Obesity and hypertension predict the presence of left atrial enlargement independently from one another. Patients presenting with both obesity and high blood pressure had a higher risk of left atrial enlargement than those showing only one condition. However, those patients with obesity were more likely to have left atrial enlargment than those who only presented with hypertension.
Certain health conditions may lead to a diagnosis of left atrial enlargement. The Ochsner Journal states that problems with the mitral valve of the heart can cause an increase in blood volume and too much pressure in the left atrium, causing it to enlarge. People who are diagnosed with left atrial enlargement have an increased risk of atrial fibrillation, stroke and death.