This absorbing and poignant book is not merely the story of one writer's flawed heart. Born in 1966 with a congenital heart defect known as the tetralogy of Fallot, Gabriel Brownstein entered the world just as doctors were learning to operate on conditions like his. He received a life-saving surgery at five years old, and since then has ridden wave after wave of medical innovation, a series of interventions that have kept his heart beating. This is both a memoir of a life on the edge of medicine's reach and a history of the remarkable people who have made such a life possible. It begins with the visionary anatomists of the seventeenth century, tells the stories of the doctors (all women) who invented pediatric cardiology, and includes the lives of patients and physicians struggling to understand the complexities of the human heart.