When you have transthyretin amyloid cardiomyopathy (ATTR-CM), proteins called amyloids build up in your heart, stiffening the muscle and interfering with its ability to pump blood throughout the body.

Atrial fibrillation, or AFib, is a type of irregular heart rhythm that causes your heart to pump less effectively than it should. You’ll get treatment to try to bring back a normal rhythm. Another ...