Sir Dominic Corrigan's classic monograph On Permanent Patency of the Mouth of the Aorta, or Inadequacy of the Aortic Valves was published in 1832. Descriptions of aortic regurgitation had previously been published by others, but Corrigan's contribution was so comprehensive that his name is still closely associated with this disorder. He described the physical findings and the underlying gross pathologic anatomy of aortic regurgitation. He recognized that sudden death was not characteristic of aortic regurgitation, as it was in aortic stenosis, and his therapeutic approach was based on firm physiologic principles. In the past 150 years we have expanded Corrigan's work, and we have developed a detailed appreciation of the natural history, pathophysiology, diagnostic methods, and treatment of chronic aortic regurgitation. Fifteen years ago, cardiac catheterization and angiography had already achieved widespread application in the evaluation of aortic regurgitation, but cardiac ultrasound, especially Doppler echocardiography, was in its infancy, and the utility of radionuclide ventriculography was not widely appreciated.