Roberto M. Lang, MD, is an internationally renowned cardiologist and specialist in echocardiography, the study of heart function using sound waves. Dr. Lang uses his vast knowledge of cardiac imaging techniques to evaluate patients with a wide variety of heart conditions, including heart failure and valve disease. Dr. Lang was a pioneer in the development of three-dimensional echocardiography, a state-of-the-art method to observe heart function. He is a past president of the American Society of Echocardiography. In addition, he has been named one of the top cardiologists in Chicago by Chicago magazine. Dr Lang is currently in charge of the Valve Clinic, where he actively collaborates with interventional cardiologists, as well as cardiac and vascular surgeons, to treat patients with structural heart disease and percutaneous aortic stenosis.