Sometimes the best way to really understand something is to step inside it. With the first Spokane appearance of the world's largest interactive heart, you'll be able to do just that. The 16-foot-tall, 22-foot-wide heart allows visitors to touch, hear and learn about the heart while walking through it. The thumping AmeriHeart contains all the things a real heart does, making it easy to see how blood circulates and what the heart's sounds mean. It also illustrates some heart dysfunctions — what a hole in the heart is, how heart infection might look, and what happens during a heart attack or a coronary artery bypass procedure. The exhibit, sponsored by Washington Trust Bank, is free and open to anyone attending the Bloomsday trade show at the Spokane Convention Center, May 2 from noon to 8 pm, and May 3 from 9 am to 6 pm.