Valvular Heart Disease: Replacement and Repair

Valve surgery is very different from coronary artery bypass grafting (CABG). Over the natural history of valvular heart disease (VHD), the physiologic characteristics change markedly and, in the operating room, physiologic and hemodynamic conditions are quite variable and are readily influenced by anesthetic interventions. For some types of valve lesions it can be relatively difficult to predict preoperatively how the heart will respond to the altered loading conditions associated with valve repair or replacement. It is essential to understand the natural history of each of the major adult-acquired valve defects and how the pathophysiologic conditions evolve. Surgical decision making regarding valve repair or replacement must also be understood, because a valve operated on at the appropriate stage of its natural history will have a good and more predictable outcome than one operated on at a late stage, when the perioperative result can be quite poor. Because pathophysiologic conditions are dynamic and differ significantly among valve lesions, understanding the physiology and natural