Enlargement of the left atrium of the heart can be caused by a myriad of different disorders, diseases, and dysfunctions but is nonetheless a serious medical condition. Atrial enlargement is usually a side-effect of one of these causal factors and thus knowing the symptoms of the causes will help you understand how your left atrium became enlarged. As with any medical condition, especially one concerning the heart, it is imperative you seek medical advise immediately for proper treatment of the underlying causes.
High volumes of blood, high blood pressure, and hypertension can all cause an enlargement of the left atrium. Most of the signs and symptoms of high blood pressure are "silent," that is most people do not feel ill or any effects of blood pressure that is elevated. Some people, however, do experience irregular heartbeats, confusion, fatigue, or chest pain. The only certain way to know is to have your blood pressure checked.
Heart arrythmias, or irregular heartbeats, which are centered in the left atrium can also cause left atrial enlargement. Atrial fibrillation can be caused by problems in the electrical impulses sent tot he heart which cause the left atrium to "quiver" or fibrillate, reducing the pumping power of the heart and allowing the blood to "pool" inside the heart. Also, problems in the mitral valve--the valve that connects the left atrium with the left ventricle--can cause left atrial fibrillation. In any case, patients will feel weak, dizzy, out-of-breath, pain in the chest, and feel a fluttering of the heart.
In some cases, especially in infants, a genetic anomaly causes a defect in the heart or surrounding tissue, causing the left atrium to enlarge. Typically, infants and children will have difficulty in gaining weight, recurring lung infections, a blue tint to their skin (called cyanosis), fast breathing, and an inability to exert themselves. Adults will experience palpatations (odd beatings of the heart), shortness of breath, and the inability to exert themselves.
The heart is a muscle that can, in some cases, experience a stretching or deformation which affects its ability to pump blood. This condition, called cardiomyopathy, can cause the left atrium to enlarge causing patients to experience shortness of breath, chest pain or pressure, dizziness or fainting, and palpatations (fluttering or odd heart beats).
In some cases, prevention of atrial enlargement can be accomplished by treating the underlying cause, such as blood volume or pressure. In the case of excess blood volume, blood thinners are prescribed which can stop the atrial enlargement while in the case of high blood pressure/hypertension weight loss, exercise, and blood pressure medication can help.
In other cases, such as mitral valve deformity or dysfunction, surgery or ablation (a burning of the valve's scar tissue) may be an option your doctor will want to explore.
For muscle deformities, physicians may prescribe similar medications used to treat patients who have had heart failure, such as beta blockers and ACE inhibitors.
In some cases, however, such as genetic abnormalities, there are very few options outside of major surgery (or surgeries).