The Mayo Clinic Echocardiography Laboratory in Rochester, Minnesota, one of the largest echocardiography laboratories in the world, features state-of-the-art diagnostic, therapeutic, educational and research facilities.

More than 30 full-feature scanning stations are located throughout the Mayo Clinic Rochester complex. The echocardiography lab is staffed by approximately 50 echocardiologists, and approximately 100 cardiac sonographers performing more than 250 echocardiographic procedures each day. The Echocardiography Laboratory is also active in clinical research and education.

Teaching faculty

The Echocardiography Program is coordinated and taught by the clinical, scientific, and technical staff of Mayo Clinic. Faculty members are chosen for their commitment to teaching, as well as clinical practice or research. Many have published and lectured extensively and are highly regarded in their fields.

You'll have direct access to these individuals throughout your training, giving you the opportunity to learn from experienced practitioners in the field of echocardiography.

Sally Miller, R.D.C.S., ACS
Program Director

Sally Miller has been the Echocardiography Program Director since December of 2014 and holds the rank of Assistant Professor of Medicine at Mayo Clinic College of Medicine and Science (MCCMS). She joined the Echocardiography Program in 2008 as a clinical coordinator and was then appointed associate program director in 2013, prior to becoming Program Director. Ms. Miller graduated from the Mayo Clinic School of Health Sciences (MCSHS) Echocardiography Program in 2003 and began working in the Echocardiography Lab at Mayo Clinic in Rochester, Minnesota, as a registered diagnostic cardiac sonographer (RDCS). She then went on to complete a Bachelor’s Degree in echocardiography from the Oregon Institute of Technology, and later become credentialed as an Advanced Cardiac Sonographer (ACS). Prior to pursuing a career in echocardiography, Ms. Miller was a radiologic technologist.

Ms. Miller is very involved with professional societies, and has held positions as a board member and various committees. She has also lectured at many national and regional conferences. She was awarded the recognition of Fellow of the American Society of Echocardiography in 2011. She has also been involved in authoring educational material in echocardiography.

Abby Biers, R.D.C.S.
Clinical Coordinator

Abby Biers has been the clinical coordinator for the Echocardiography program since 2016. She graduated from the MCSHS Echocardiography Program in 2008 and became credentialed as a registered diagnostic cardiac sonographer (RDCS) through the American Registry of Diagnostic Medical Sonography. Upon graduation, Ms. Biers began working in the Echocardiography Lab at Mayo Clinic in Rochester, Minnesota, as a cardiac sonographer, becoming a clinical instructor a year later. Her interests include 3-D echocardiography, clinical instruction, and education. In September of 2017, she was appointed the academic rank of Instructor in Medicine by Mayo Clinic College of Medicine and Science. She is the primary instructor of the clinical practicum courses and scan labs on the Minnesota campus, and also works with students in the clinical area.

Prior to her career in echocardiography, Ms. Biers attained her Associate of Applied Science degree radiologic technology and worked as radiologic technologist for several years, and then attained a bachelor’s degree in human services.

Allison Huver, R.D.C.S.
Associate Program Director, Academic Coordinator

Allison Huver is the Associate Program Director and academic coordinator for the MCSHS Echocardiography Program. She graduated from the University of Minnesota - Rochester with a Bachelor of Science in Health Professions degree along with a certificate of completion from the MCSHS Echocardiography Program in 2017.

Since graduating, Ms. Huver has worked as a cardiac sonographer in the Echocardiography Lab at Mayo Clinic in Rochester, Minnesota. In 2019, she became the education assistant for the MCSHS Echocardiography Program and transitioned to the role of academic coordinator in 2021. As the academic coordinator, Ms. Huver's responsibilities include coordinating academic schedules, curriculum design, assisting with program accreditation, and teaching a variety of academic courses and scan labs. Her experience and interests include adult echocardiography, education, and ergonomics. 

Ms. Huver is credentialed through the American Registry for Diagnostic Medical Sonography in Adult Echocardiography. She achieved the academic rank of Instructor in Medicine by MCCMS in 2021. She is a member of the American Society of Echocardiography and was awarded the recognition of Fellow of the American Society of Echocardiography in 2025.

Zachary Barrett-O'Keefe, Ph.D., R.D.C.S.
Academic and Clinical Instructor

Zachary Barrett-O'Keefe is an adjunct academic and clinical instructor in the Echocardiography program and a Research Scientist at Mayo Clinic Rochester. Dr. Barrett-O'Keefe earned his B.A. in human physiology from the University of Oregon in 2009 and his Ph.D. in integrative physiology from the University of Utah in 2015. He subsequently trained in adult echocardiography in the MCSHS Echocardiography Program followed by an appointment to the echocardiography lab staff at Indiana University Methodist Hospital, where he had the opportunity to train under Dr. Harvey Feigenbaum, a pioneer in the field of echocardiography. Dr. Barrett-O'Keefe joined the echocardiography lab at Mayo Clinic in Rochester, Minnesota, in 2018, and transitioned to a research sonographer position within the Mayo Clinic Echocardiography and Vascular Physiology Research Unit in 2019. He primarily assists Alexander Egbe, M.B.B.S., M.P.H., in his research practice, investigating ventricular and arterial hemodynamics and their interaction during physical stress in patients with congenital heart disease.

Sarah Dunn, R.D.C.S.
Academic and Clinical Coordinator, Rochester campus

Sarah Dunn started her career at Mayo Clinic Rochester in 2004 as a Phlebotomist in Laboratory Medicine. Ms. Dunn then graduated from the MCSHS Echocardiography program in Rochester in 2013. She is a registered diagnostic cardiac sonographer (RDCS) through the American Registry of Diagnostic Medical Sonography and has been a cardiac sonographer in the Mayo Clinic Rochester Echocardiography lab since 2015. Ms. Dunn also received her Bachelor of Science in Health Professions from the University of Minnesota Rochester in 2015.

Ms. Dunn thoroughly enjoys working as a clinical instructor with the cardiology fellows and the echocardiography students. She is one of the primary clinical instructors for the students for inpatient hospital echocardiography and interventional procedures. Ms. Dunn’s interests include adult echocardiography, pericardial disease and cardiac catheterization procedures.

Students on the Arizona campus are required to spend a week on the Rochester campus attending various labs and courses near the beginning of the program.

The Mayo Clinic Echocardiography Laboratory in Arizona is one of the most progressive laboratories in the Southwest. The lab administers up to 180 exams a day and is staffed with 19 echocardiologists, 38 cardiac sonographers, and 3 advanced clinical sonographers. The lab is active in clinical research and education and is a clinical site for the Echocardiography Program.

Teaching faculty

The Echocardiography Program is coordinated and taught by the clinical, scientific, and technical staff of Mayo Clinic. Faculty members are chosen for their commitment to teaching, as well as clinical practice or research. Many have published and lectured extensively and are highly regarded in their fields.

You'll have direct access to these individuals throughout your training, giving you the opportunity to learn from experienced practitioners in the field of echocardiography.

Christy Baxter, R.D.C.S.
Academic and Clinical Coordinator, Arizona Campus

Christy Baxter started her career at Mayo Clinic in Phoenix, Arizona, in 2003 working as a research technologist in cardiovascular research. In 2006, she began working in the echocardiography lab as a cardiac sonographer and clinical instructor and then joined the Echocardiography Program faculty in 2020. She graduated with her bachelor's degree in Biological Sciences in 2001.

Ms. Baxter's interests include adult echocardiography, stress echocardiography, and carotid intima-media thickness (CIMT) testing. She has participated in many research studies and has co-authored several peer-reviewed articles published in echocardiography journals, including the Journal of the American Society of Echocardiography.

Ms. Baxter is a registered cardiac sonographer (RDCS) through the American Registry of Diagnostic Medical Sonography and is also credentialed as an advanced cardiac sonographer (ACS) by Cardiac Credentialing International. She is a member of the American Society of Echocardiography and was appointed the academic rank of Instructor in Medicine by through Mayo Clinic College of Medicine and Science.

Bobbi Jo Heon, R.D.C.S., ACS
Lead Clinical Educator, Arizona Campus

Bobbi Jo Heon has been a cardiac sonographer since 2016 and joined the Echocardiography Program faculty in 2021. She graduated from Southeast Missouri State University in Cape Girardeau, MO, with a Bachelor of Science in Speech-Language Pathology. She graduated from the MCSHS Echocardiography Program in 2016 and the Advanced Cardiovascular Program in December 2021. 

Mrs. Heon is responsible for coordinating the student clinical experience and teaching clinical practicum courses, scan labs, and works with students in the clinical area on the Arizona campus. She is also involved in training cardiology fellows the basics of cardiac ultrasound. She is the primary RSS coordinator for the Arizona Echocardiography Conference and is responsible for scheduling educational activities for CME credit for the Mayo Clinic School of Continuous Professional Development (MCSCPD). Her interests include 3-D echocardiography, strain-imaging, and stress echocardiography. In 2021, she was appointed the academic rank of Instructor in Medicine by MCCMS. She is also credentialed as an advanced cardiac sonographer (ACS) by Cardiac Credentialing International (CCI) and is the Associate Program Director of the Advanced Cardiac Sonography program within MCSHS.

Students on the Wisconsin campus are required to spend a week on the Rochester campus attending various labs and courses near the beginning of the program. Students may also need to travel to Rochester a few other times to participate in specific lab or clinical settings that are not available on the Wisconsin campus. These additional times are very minimal.

The Mayo Clinic Health System Echocardiography lab in Eau Claire, WI, is a leader in the NWWI market. The lab is staffed with a dedicated team of 12 cardiac sonographers, two advanced clinical sonographers, and one support staff. Approximately 55 exams are completed each day. There are 12 echocardiologists who rotate through the echo service two per day. The echo lab is a clinical instruction site for the Echocardiography school located on the Eau Claire campus with a wealth of opportunity. A comprehensive approach to cardiovascular care is further enhanced by the robust structural heart, electrophysiology, and cardiovascular surgery program.

Teaching faculty

The Echocardiography Program is coordinated and taught by the clinical, scientific, and technical staff of Mayo Clinic. Faculty members are chosen for their commitment to teaching, as well as clinical practice or research. Many have published and lectured extensively and are highly regarded in their fields.

You'll have direct access to these individuals throughout your training, giving you the opportunity to learn from experienced practitioners in the field of echocardiography.

Mary Wright, R.D.C.S
Academic and Clinical Coordinator, Eau Claire Campus

Mary Wright is an Academic and Clinical Coordinator for the MCSHS Echocardiography Program.  She has been a cardiac sonographer since 2002 and joined the Echocardiography Program Faculty in 2023.  She graduated from the University of Wisconsin-Eau Claire with a Bachelor of Science in Chemistry with a Business Emphasis.  She graduated from Argosy University -Twin Cities with an Associate degree in Diagnostic Medical Sonography in 2002.  Mrs. Wright is a registered diagnostic cardiac sonographer (RDCS) through the American Registry of Diagnostic Medical Sonography (ARDMS) and is also credentialed in Vascular, Abdomen, and Ob/Gyn through the ARDMS.  She is also a member of the American Society of Echocardiography.

Mrs. Wright’s responsibilities include teaching a variety of academic courses and scan labs as well as helping with instructing students and clinical instructors in the clinical area on the Wisconsin campus.  Her interests include Adult and Congenital Echocardiography, TEE, and Stress Echocardiography.