Right atrial mural thrombi: An autopsy study of an under-diagnosed complication at an unusual site.

Background: Right atrial mural thrombi (RAMT) are often seen in association with cardiac diseases or foreign bodies. Unusual locations at the flutter isthmus and the atrial appendage prompted us to evaluate our 2-year autopsy data on such thrombi. Materials and Methods: In the 2-year retrospective autopsy, the clinical and autopsy records of patients with RAMT were reviewed, with particular reference to the presence of central venous catheter (CVC), its site of insertion, its type, material and size, its duration of placement, and the drugs infused through the catheter. Results: Of the 940 autopsies performed in 2 years, RAMT was seen in 24 hearts and was related to an insertion of a CVC in 23 patients (95.8%). The risk and/or associated factors for this complication were tunneled and polyethylene catheters, Intensive Care Unit admission, infused drugs, underlying cardiac diseases, and pregnancy. A noteworthy feature was the location of the thrombi in the flutter isthmus in 16 hearts (66.7%) and atrial appendage in another six hearts. Localized endocarditis/myocarditis and pulmonary thromboembolism were observed in six and four patients, respectively.Conclusions: This autopsy study, which has a high incidence of catheter-related RAMT, does not reflect the true incidence but reiterates the importance of guided insertion of central venous and prompt recognition of thrombus formation.