May Be Caused by

 Common

Atrial septal defect

Atrioventricular canal defect

Chronic left heart failure

Cor pulmonale

Left ventricular-right atrial shunt

Mitral stenosis

Patent foramen ovale

Pulmonic stenosis

Right heart failure

Right ventricular enlargement

Right ventricular hypertrophy

Ruptured sinus of Valsalva aneurysm

Tetralogy of Fallot

Tricuspid insufficiency

Trilogy of Fallot

 Uncommon

Atrial aneurysm

Congenital atriomegaly

Coronary artery fistula to right atrium

Ebstein anomaly

Endocardial fibroelastosis

Endomyocardial fibrosis

Hypoplastic left heart syndrome

Neoplasm of right atrium

Neoplasm of right ventricle

Post-mitral valve replacement

Pulmonary atresia

Transposition of great vessels with interatrial communication

Tricuspid atresia

Tricuspid stenosis

Uhl anomaly