Mild left atrial enlargement usually does not affect the life expectancy of patients, while patients with severe left atrial enlargement complicated by heart failure have a 4-year survival rate of only 50%. Common causes of left atrial enlargement include hypertension, rheumatic heart disease, coronary artery disease, and cardiomyopathy. In patients with mild left atrial enlargement, if there are no symptoms such as chest pain, chest tightness, palpitations and other complications, there is usually no significant impact on life expectancy; if patients with left atrial enlargement are combined with serious underlying diseases, such as rheumatic heart disease, severe mitral stenosis or incomplete closure, and complicated by atrial fibrillation and heart failure, life expectancy will be affected, and the 4-year survival rate for patients with complicated by severe heart failure is only 50%. Patients with left atrial enlargement should be treated for the cause, such as appropriate antihypertensive therapy for patients with hypertension, treatment to improve myocardial ischemia for patients with long-term myocardial ischemia, and basic therapy for patients with rheumatic heart valve disease for the cause.