1 Mayo Clinic Cardiovascular Ultrasound Imaging and Hemodynamic Laboratory, Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota; Division of Cardiovascular Diseases, Assiut University, Assiut, Egypt.
2 Mayo Clinic Cardiovascular Ultrasound Imaging and Hemodynamic Laboratory, Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
3 Division of Cardiovascular Diseases, Rush University, Chicago, Illinois.
4 Mayo Clinic Cardiovascular Ultrasound Imaging and Hemodynamic Laboratory, Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota; Division of Cardiovascular Diseases, Dalhousie University, Halifax, Nova Scotia, Canada.