Cardiac arrest in a patient with a mobile right atrial thrombus in transit and amyloidosis.

Primary amyloidosis is a rare disorder in which insoluble fibers are deposited in tissue and organs, impairing their function. Cardiac involvement occurs in up to 50% of patients with primary amyloidosis. We describe a case of a 75-year-old admitted to our department after he had a sudden cardiac arrest due to massive bilateral thrombotic occlusion of the pulmonary arteries. The echocardiogram revealed many atrial thrombi swirling inside the right atrium and protruding into the tricuspid valve partly occluding it. Severe concentric hypertrophy of the left ventricle was also present with a preserved ejection fraction. The right ventricle was dilated, hypertrophic and ipokinetic with a severe tricuspidal insufficiency that permitted estimation of a severe pulmonary hypertension. All these characteristics were highly suggestive for an infiltrative form of hypertrophic cardiomyopathy. The final diagnosis was amyloidosis.