The Case of Isolated Double Atrial Septum with Persistent Interatrial Space
A 69-year-old male was consulted to cardiology from otolaryngology for pre-operative cardiac evaluation. He had a history of hypertension with no event of cerebrovascular accidents. And he had an operation schedule for oral cavity cancer involving right buccal mucosa (T4N0M0, in TNM staging). His general condition looked poor because of oral cavity malignancy and concurrent chemotherapy. His blood pressure was 103/62 mmHg and pulse rate was 95 bpm with regular heart beat. Chest X-ray showed mild pulmonary edema and bilateral pleural effusion 1 week ago, but improving with negative volume control.\nTwo-dimensional echocardiography showed normal LV systolic function with LV ejection fraction about 56%, concentric hypertrophy of LV and slightly enlarged left atrial (LA) chamber with LA volume index 55 mL/m2. Apical 4 chamber () and parasternal views showed fibrothickened with calcification of mitral valve and aortic valve due to rheumatic heart disease with moderate mitral stenosis (mitral valve area 1.55 cm2, mean diastolic pressure gradient 5.5 mmHg), moderate aortic stenosis (aortic valve area 1.21 cm2, peak/mean systolic pressure gradient 34/19 mmHg) and interatrial septal aneurysm. It also showed mild pulmonary hypertension with 41 mmHg of right ventricular systolic pressure, and inferior vena cava plethora suggestive diastolic heart failure.\nOn standard parasternal and apical views, there was no definite abnormal finding at interatrial septum except aneurismal change of interatrial septum (). However, on subcostal view, there was 3.2 × 1.0 cm sized, crescent shaped, echo-free space was observed between two atria (). This echo-free space was located in center of interatrial septum and consisted of parallel atrial septal structure (). It was highly suspicious of double atrial septum with persistent interatrial space. There is no evidence of thrombus in this space and color Doppler echocardiography revealed communicating flow between this space and LA and small amount of left-to-right shunt flow suggesting patent foramen ovale (PFO) (). The computed tomography (CT) also identified double-layered parallel atrial septal structure with persistent interatrial space, showing contrast enhancement (). We recommended further evaluation for double atrial septum including transesophageal echocardiography (TEE) but patient refused because of oral cavity lesion and had surgery (wide excision of buccal mucosa cancer) at otolaryngology. He was prescribed aspirin and has followed up uneventfully to date.