1 Saint Luke's Mid America Heart Institute, University of Missouri-Kansas City, Kansas City, MO. Electronic address: jokeefe@saint-lukes.org.
2 Saint Luke's Mid America Heart Institute, University of Missouri-Kansas City, Kansas City, MO.
3 Department of Cardiovascular Diseases, John Ochsner Heart and Vascular Institute, Ochsner Clinical School-The University of Queensland School of Medicine, New Orleans, LA.