Book excerpt: T e four heart valves reside in the center of the heart. T is indicates their crucial role in cardiac performance. Fau- less function of the valves is a prerequisite for unidir- tional forward movement of the blood, and such function is necessary to support the ef orts of the cardiac atria and ventricles. Healthy heart valves function gracefully and of er mechanical durability. Bioengineers have to marvel at the biomechanical evolution of these perfectly placed valves. Heart valves can be involved in pathological processes, however, and only then do we realize just how indispensable they really are. At one time, serious valve disorders used to be a matter of life and death for patients. Only in recent decades have surgeons been able to reverse the ominous course of heart valve disease and of er patients a quality of life and life span comparable to that of healthy persons. T e story of this ef ort began approximately 100 years ago, and today heart valve surgery is a substantial subspecialty of cardiac surgery, with accumulated experience in indications, procedures, risks, and outcomes. T e aim of this book is to present a richly illustrated compendium of the present knowledge related to heart valve surgery, based on the clinical expertise of the authors as well as the newest treatment modalities. T e authors thank Dr. Alireeza Matloobi from the Mayo Clinic for his help in preparating the book.