The right atrium is the first entry point of blood returning to theheartfrom circulating in the body.
This article covers the signs and complications of right atrial enlargement.
It also discusses the causes, diagnosis, and treatment.

Science Photo Library / Getty Images
There are several types ofcardiomegaly,or heart enlargement.
How Big Is Too Big?
There have been rare cases in which the right atrium can hold 700 mland even 1,900 ml.

Different types of right atrial enlargement are classified by how or when the problem develops.
Possible symptoms include:
When Is Discomfort an Emergency?
In many cases, there is a domino effect of one problem leading to another.
For example, valve disorders like tricuspid regurgitation can cause pressure imbalances, resulting in conditions like pulmonary hypertension.
In time, pulmonary hypertension can lead to atrial enlargement or more severe cardiomegaly and heart failure.
Your doctor will also perform a physical exam and listen to your heart and lungs.
You may even have blood work done to check your overall health and wellness.
One of the tools your healthcare provider will use is anelectrocardiogram(ECG or EKG).
It measures the electrical signals of your heart and how well its electrical and pumping systems are working.
However, it’s usually more accurate for diagnosing left atrial enlargement than right atrial enlargement.
Pressures and sizes can also be measured.
Complications
A number of serious complications can occur with right atrial enlargement.
This may include:
Lifestyle factors may also be helpful for heart and lung health.
A diagnosis of right atrial enlargement should immediately trigger an evaluation to determine the underlying cause.
Treatment will be determined by the results of that evaluation.
2014 Apr-Jun;12(46):110-2. doi: 10.3126/kumj.v12i2.13655.
2019 ; 13(4):e92367.
Long MA.Giant Right Atrium: An Extreme Case of Idiopathic Dilation of the Right Atrium.Ann of Thorac Surg.
2014;98(5):1815-1818. doi:10.1016/j.athoracsur.2013.12.082.
Harrigan RA, Jones K.ABC of clinical electrocardiography.
Conditions affecting the right side of the heart.BMJ.
2022;9:989012. doi:10.3389/fcvm.2022.989012
American Heart Association.The American Heart Association diet and lifestyle recommendations.