C. Chow

An unusual finding in the right atrium

Clinical introduction A 66-year-old asymptomatic patient underwent a routine transthoracic echocardiogram prior to commencement of clozapine, and was found to have a mobile echogenic structure in the right atrium, which was later confirmed on transoesophageal echocardiogram to be adjacent to the insertion of inferior vena cava. Follow-up cardiovascular MRI (CMR) revealed a mobile, avascular 2.1×2.2 cm2 mass with regular and smooth borders, adjacent to the eustachian valve (Figure 1 panel A: coronal view; online supplementary movie 1). Late gadolinium enhancement (LGE; panel B) demonstrated heterogeneity, and T1-imaging demonstrated mild hyperintensity (panel C). There was no evidence of obstructive haemodynamic compromise. The mass was subsequently resected, and the histology (H&E staining, magnification ×100) is shown in panel D. Question The diagnosis of this mass is: Aberrant liver Angiosarcoma Atrial myxoma Renal cell carcinoma Thrombus

The Applicability of the American College of Cardiology Appropriate Use Criteria for Myocardial Perfusion Scintigraphy in Australia

BACKGROUND The American College of Cardiology (ACC) Appropriate Use Criteria (AUC) for radionuclide myocardial perfusion scans (MPS) was developed to promote its rational use in the assessment of stable ischaemic heart disease (IHD). We sought to validate the applicability of this document in the Australian context. METHODS 1009 consecutive patients who underwent MPS were retrospectively audited at a single major metropolitan hospital in Victoria, Australia. Appropriateness was assigned based on the 2013 ACC AUC, and common indications and predictors of positive scan results were examined. RESULTS The AUC was successfully applied (99.1%) retrospectively. A large proportion of scans were deemed appropriate (82.7%), whilst 7.8% were maybe appropriate. Positive detection rates in these groups were 17.0% and 17.9% respectively. Eighteen patients (1.8%) were unclassifiable, but had a detection rate of 44.4%. Positive predictors of an abnormal MPS result included prior history of coronary artery disease, typical angina, and following the conservative management of an acute coronary syndrome. Scans that were rarely appropriate had a detection rate of 0%. CONCLUSION The retrospective application of the 2013 ACC AUC is feasible. Whilst the majority of the scans were appropriate, a group of unclassifiable patients was observed to have a high detection rate. Scans that were rarely appropriate could potentially be rationalised to reduce radiation risk.