Aortic regurgitation is a heart condition where the aortic valve does not close properly, allowing blood to flow backward from the aorta into the left ventricle during diastole. This can lead to an increase in the volume of blood in the left ventricle, causing it to enlarge and potentially weaken over time. Common causes of aortic regurgitation include congenital heart defects, rheumatic fever, and aortic dissection. Symptoms may include fatigue, shortness of breath, and palpitations. Diagnosis is typically made through echocardiography, which helps assess the severity of the condition and guide treatment options.