Left Atrial Diverticula Supplied by the Anomalistic Branch of the Right Coronary Artery

We have reported several cases of pulmonary vein thrombosis in elderly individuals with or without chest pain; pulmonary vein thrombosis is common in aged individuals and should be evaluated further. However, the properties and roles of pulmonary vein thrombi (PVTs) have not been determined. During infection, neutrophil extracellular traps (NETs) are produced to kill pathogens, and arterial thrombi (ATs) are produced in pulmonary veins to prevent pathogens from spreading to all organs. We reported that fine PVTs became larger PVTs and extended to the LA wall. PVTs can cause acute myocardial infarction (AMI) and ischemic stroke (IS) by releasing larger particles; therefore, the characteristics of PVTs need to be determined to prevent the occurrence of AMI and IS. PVTs can cause several diseases by releasing smaller particles, such as NETs, for which cumulative effects should be determined. PVTs and their effects on human health need to be studied to avoid missing the chances of treating patients with these diseases moderately. We reported that PVTs often extend to the left atrium (LA) and attach to the LA wall; however, the effects of attachment remain unclear. According to cardiac computed tomography (CT), left atrial diverticula (LADs) reportedly occur in 10%-50% of patients; however, the details of the LAD are unknown. Therefore, we examined the relationships among PVTs, LA thrombi, and LADs using cardiac CT and transesophageal echocardiography (TEE). The patient was a 65-year-old male with hypertension and severe palpitations. He had no history of AMI or IS. TEE revealed that the LA thrombi were attached to the anterior wall of the right lower pulmonary vein and that they were attached to the anterior wall of the LA. TEE revealed an LAD near the attachment area. Cardiac CT revealed an LAD without thrombi near the attachment area. Sagittal images from a cardiac CT scan revealed that a part of the attachment region in the LA was a dark line, where no blood flow was observed in the LA, and that there seemed to be the LAD on top of the dark line. The anomalistic branch of the right coronary artery (#1) connected around the top of the LAD.