Objective: To explore the characteristics of intra-cardiac blood cysts to provide a reference for accurate diagnosis and prognosis. Methods: In this study, 8 cases of cardiac blood cysts were analyzed retrospectively from January 2006 to March 2020, and the clinical symptoms, echocardiography, operation and prognosis were analyzed. Results: All clinical symptoms were not typical and cysts were isolated. The cysts were attached to the anterior leaflet of the mitral valve (n=4), posterior papillary muscle and chordae of mitral valve (n=1), septal leaflet of the tricuspid valve (n=2), or the tricuspid valve orifice and tricuspid anterior annulus (n=1). Echocardiography revealed the cysts were small and balloon‑like. They had high tension wall, the wall was thin and smooth. Calcification could be seen on the cyst wall. The inside was none echogenicity area and the cyst moved and swung with the valve or chordae. Of the 8 patients, 1 had no hemodynamic effects and did not need surgery. The other 7 cases were confirmed by surgery and pathology for the cardiac blood cysts. 3 subjects underwent simple cystectomy alone. 1 with infectious endocarditis and mitral valve vegetation, and the other one caused the left ventricular outflow tract obstruction. 2 subjects had a history of mitral valve abnormality with mechanical mitral valve replacement. Conclusions: Cardiac blood cysts are rare and benign heart condition in adults. They can be diagnosed by echocardiography to guide intervention.

Objective: To explore a new method of differential diagnosis of fetal double aortic aorta (DAA) and right aortic arch with mirror-image branches (RAA-MB). Methods: Clinical data and prenatal echocardiographic features of the DAA (n = 22) and RAA-MB (n = 65) confirmed by postnatal or autopsy findings were analyzed retrospectively. The angles between the two aortic arches in the DAA group and between the right aortic arch and the mirror branch were measured. The differences between both groups and differential diagnosis value of the angles were compared and analyzed based on the ROC curve. Results: Left-sided DAA’s proportion (100%) was higher in the double aortic arch group (32.3%) than in the RAA-MB group, (P ＜ 0.05). The proportion of conotruncal anomalies is higher in the RAA-MB group (64.6%) than in the DAA group (18.2%) (P ＜ 0.05). There was a significant difference in the angles between both groups (DAA: 50.3° ± 8.3° vs RAA-MB: 82.9° ± 13.8°) (P < 0.01). When the cut-off value was 62.8°, the sensitivity and specificity of differential diagnosis were 95.5% and 96.9%, respectively. Conclusions: Distinguishing the angle measurement between DAA and RAA-MB is helpful in prenatal prognosis. We recommend a cutoff value of 62.8°.