Right Atrial Myxoma and Syncope

BACKGROUND Right atrial myxoma accounts for 15-20% of cardiac myxomas and syncope is a very rare manifestation. We present the case of an 89-year-old man with right atrial myxoma and syncope, and discuss the role of cardiac magnetic resonance imaging (MRI) in the diagnosis of myxomas. CASE REPORT An 89-year-old man with a history of hypertension, hyperlipidemia, chronic kidney disease stage 4, mild dementia, and benign prostatic hyperplasia presented to the emergency department with an episode of syncope. Physical examination demonstrated normal and regular heart sounds, and normal respiratory rate and oxygen saturation. Echocardiogram described a well-circumscribed echo-dense mass in the right atrial cavity, which was attached to the septum but not obstructing the tricuspid annulus, measuring 1.7×2.2 cm at its widest diameter. Cardiac MRI revealed a mass with dark intensity which enhanced heterogeneously following intravenous administration of gadolinium-chelate, consistent with a myxoma. The location of this myxoma, coupled with the presence of a stalk allowing mobility, provides a clue to how this patient experienced transient obstruction of the tricuspid valve leading to syncope. CONCLUSIONS Right heart tumors should be considered in the differential diagnosis of unexplained syncope. Cardiac MRI with gadolinium-chelate administration can help differentiate this tumor from a right-sided atrial thrombus, which can pose a diagnostic challenge.