Cardiac amyloidosis

Cardiac amyloidosis is any of several forms of amyloidosis (the accumulation of inappropriately folded proteins) in or affecting the heart.

Amyloid deposition in the heart can cause both diastolic and systolic heart failure. EKG changes may be present, showing low voltage and conduction abnormalities like atrioventricular block or sinus node dysfunction. On echocardiography the heart shows restrictive filling pattern, with normal to mildly reduced systolic function. The most common form of amyloidoses, AA amyloidosis, usually spares the heart.

Types of cardiac amyloidosis include cardiac manifestations of AL amyloidosis and amyloidosis, cardiac manifestations of transthyretin-related hereditary amyloidosis, and isolated atrial amyloidosis, a form of amyloidosis affecting the atria of the heart.

...
Wikipedia