There is only one cause.
My penis.
It is WAY too big to fit,
so they had to enlarge the atrium.
An enlarged atrium can develop an erratic rhythm (atrial fibrillation), which reduces its efficiency and can lead to blood clots forming in the atrium.
An excessive overload of the left atrium in the human heart is referred to as Left Atrial Enlargement. It can be caused by hypertension, obesity or congestive heart failure.
Enlargement of the atrium.
There may be many causes of an enlarged left atrium to include mitral stenosis, mitral regurgitation and left ventricle failure. Other causes are ventricular septal defect and patent ductus arteriosus.
Left atrial enlargement is a not uncommon condition in adults. It means the left atrium of the heart (which holds blood before it goes into the left ventricle) is enlarged. This can happen for a number of reasons. Lung or heart disease are probably the most common reasons, but problems with the mitral valve can also result in left atrial enlargement - either a stiff valve that does not open well, or a "leaky" valve through which blood can go backwards in the heart.
Mitral regurgitation
the size of the right atrium is smaller that the left atrium.
Oxygenated blood flows from the lungs to the left atrium contractions (heart muscle) cause the blood to leave the atrium and enter the left ventricle. Further contraction causes the blood to leave the atrium and enter the aorta.
The left atrium empties into the left ventricle. The left atrium and left ventricle are separated by the left AV valve, or mitral valve.
Right Atrium , Left Atrium , Right Ventricle , Left Ventricle
the left atrium
the left atrium...it pumps blood thereThe pulmonary vein carries oxygenated blood from the lungs to the left atrium of the heart.
The two upper chambers are called the atria. A single atria is an atrium.