Cardiac amyloidosis presumptively diagnosed as cardiac syndrome X.

A 75-year-old man with cardiac amyloidosis was presumptively diagnosed as having cardiac syndrome X. Early clinical presentation was repeated episodes of angina pectoris without angiographically significant stenosis of the coronary arteries, so the diagnosis of cardiac syndrome X was initially given. However, his anginal symptoms worsened despite appropriate medication. He developed congestive heart failure and died 8 years after his first anginal symptoms. Autopsy revealed amyloid deposits in the intramyocardial coronary arteries with luminal obstruction, with little in the epicardial coronary arteries or myocardium. Therefore, the definitive diagnosis was cardiac amyloidosis.