Cerebral embolism due to atrial myopathy in a cardiac amyloidosis patient diagnosed by cardiac magnetic resonance imaging

A 55-year-old woman was admitted with heart failure. On the third hospital day, she suddenly developed cerebral infarction. The resting 12-lead electrocardiography showed normal sinus rhythm, and atrial fibrillation or flutter were never detected on electrocardiographic monitoring throughout the whole hospital days. She had no other conventional risk factor for cerebral infarction. Transthoracic echocardiography showed left ventricular hypertrophy. Transesophageal echocardiogram revealed strong spontaneous echo contrast in the left atrium (LA), and the blood flow in the left atrial appendage was extremely decreased (22.3 cm/s). Late gadolinium enhancement in cardiac magnetic resonance (CMR) imaging showed global subendocardial hyperenhancement of the left ventricle and both atria. Endomyocardial biopsy specimen was positive for amyloid by Congo red staining. Marked amyloid infiltration to both atria might cause atrial dysfunction leading to thrombus formation in the LA. CMR is thought to be a useful noninvasive tool to detect atrial myopathy in cardiac amyloidosis patients.