To circulate blood effectively and efficiently, the heart's four chambers must beat in a steady, coordinated way. Trouble brews when they don't. Take atrial fibrillation, the most common type of serious irregular heart rhythm. The top chambers (atria) beat fast and erratically. When that happens, the atria look like a pulsating bag of worms.
This multitouch book from Harvard Health Publications covers the medical background of atrial fibrillation, and includes original 3D renders and videos, interactive diagrams and other content, and text from the renowned team at Harvard Medical School.