Right atrium (RA) enlargement is a very frequent finding in patients with pulmonary arterial hypertension (PAH) and also a marker of mortality, though its relation to atrial arrhythmias risk has not been assessed.

Enlargement of the right atrium (RA) is seen with an increased risk for supraventricular arrhythmias (SVAs) along with pulmonary arterial hypertension (PAH), according to a recent study.

Investigators appointed 97 consecutive adult patients with PAH from 2010 to 2014 and kept a track of those patients until January 2017. Treatment-naïve patients and patients with a history for PAH were included in this study. The investigators also looked into specific indicators  of newly diagnosed clinically significant SVA (csSVA) in patients with no history of SVA at enrollment.

Right atrium enlargement has several names, including right atrium hypertrophy, overgrowth, or enlargement. There are subtle differences between the diagnoses, but they all have the same result: the heart has more right atrium than normal. The atria may contain more blood until the increased blood volume reaches the next chamber of the medium-sized heart. There are different types of cardiac hypertrophy or heart enlargement. Enlargement can affect the entire heart or specific chambers. You may be born with this disease, or you may develop it due to chronic diseases such as high blood pressure.

A normal right atrium can hold 11 to 40 milliliters (ml) of blood at a time. 1 In people with enlarged atria, the atria can hold more blood. In rare cases, the right atrium can hold 700 ml2 or even 1900 ml. Different types of right atrium enlargement are classified according to how and when the problem develops. Idiopathic right atrial enlargement (IERA) is a rare disease with or without other heart problems. Due to many other heart problems or conditions, such as high blood pressure or valve disease. Purpose is To evaluate whether increased RA is associated with supraventricular arrhythmia (ALS) and prediction of a new clinically significant ALS (csSVA).

a study recruited Patients with PAH between January 2010 and December 2014 and followed until January 2017. csSVA was diagnosed in case it resulted in hospitalization. To assess predictors of new csSVA, only patients without a history of SVA at baseline were analyzed.

Among 97 patients, 45 (46.4%) observed any AVS, including persistent atrial fibrillation (AF, n = 8), paroxysmal AF (n = 10), persistent atrial flutter (AFl, n = 1), paroxysmal AF (n = 1) = 2) or other types of supraventricular tachycardia (n = 24) atrial area, right mean atrial pressure (mRAP), and more frequent use of beta blockade Agent treatment. 85 patients with sinus rhythm and no obvious history of ABC at the first visit were followed up for 37 ± 19.9 months. In univariate models, the occurrence of csSVA is predicted based on age, right ventricular ejection fraction, right ventricular end-diastolic index, RAai and mRAP, but in multivariate models, only RAai is still an important predictor of csSVA (HR 1.23, 95 % CI: 1,111.

Diagnosis of left atrium enlargement is usually more accurate than right atrium enlargement. Atrial fibrillation and related atrial tachyarrhythmias, including type I atrial flutter, are common in patients with pulmonary hypertension. Evidence of increased wedge pressure and enlargement of the left atrium, especially in patients with AF, indicates simultaneous involvement of the atrial basement and arrhythmia, although there is invasive evidence of purely isolated anterior capillary PH. Significant differences were observed between patients with type I CHD and patients with other types of arrhythmias. Hypertension indicates that the left atrial matrix plays a role in the arrhythmia of complex atrial tachycardia, even in the presence of pure anterior capillary PH.

In PAH patients RA enlargement is linked with increased occurrence of SVA.