Talented and dedicated researchers are at work every day across the Texas Health Resources system. Learn more below about some of these gifted individuals who are making a difference in the lives of patients everywhere.

Benjamin Levine, M.D.

Benjamin Levine, M.D. Janelle Knight of Mount Vernon, Iowa, has never met Dr. Benjamin Levine, but she probably won't soon forget him. After all, this Dallas cardiologist's research did help save her life.

After recovering from the flu, Knight, a varsity high school athlete, suddenly could not walk more than a few feet without feeling lightheaded or fainting. She was only able to attend school using a wheelchair for a few hours at a time. Her heart raced rapidly, she constantly felt weak and had debilitating headaches.

After months of tests, Knight was diagnosed with POTS - postural orthostatic tachycardia syndrome - a disorder characterized by an excessive heart rate in the upright position and an intolerance to prolonged standing.

POTS can be brought on after long periods of bed rest, as in Knight's case. The condition is also found in people with smaller hearts that do not fill adequately in the upright position. POTS is most common in young adults, although it can affect adults at any age. POTS is more prevalent in women than men. The condition is often misdiagnosed or overlooked because its symptoms are common to other cardiac conditions.

"When we stand up, blood is pulled into the lower part of the body by gravity," explains Levine. "When the heart becomes deconditioned after bed rest or if it is abnormally small, it lacks the ability to compensate for the redistribution of blood below the heart. POTS patients can't pump enough blood per heart beat, so they have to pump faster at a high heart rate."

Knight was prescribed medications, including beta blockers, but they did not alleviate her symptoms. Desperate for answers, Knight's parents scoured the Internet. Her father came across a blog with information about a POTS-related exercise study conducted by Levine and his team at the Institute for Environmental and Exercise Medicine (IEEM) at Texas Health Presbyterian Hospital Dallas.

Levine, Medical Director of the IEEM, began studying the exercise benefits for POTS patients around 2001 through a NASA-funded research project. His research found that astronauts demonstrated POTS-like symptoms, including cardiac deconditioning and orthostatic intolerance, after returning from zero-gravity space missions.

IEEM researchers developed and tested an exercise regimen that allows patients to enlarge and strengthen their hearts using low intensity training. Patients start on a rowing machine or recumbent bike for 20 to 30 minutes at least three days per week. This position helps the patient avoid standing upright to exercise.

Over time, patients increase the frequency and duration of exercises and eventually progress to a stationary bike, elliptical machine, swimming laps and weight lifting. Even though the program is only three months long, patients are encouraged to continue the exercises throughout their lifetime.

Dr. Qi Fu, a research scientist at the IEEM, says that she has seen some patients, once bed ridden, able to run a mile after mere weeks in the program. Most patients experience a reduction or elimination of POTS symptoms altogether, she explains. After following the exercise program, Knight saw dramatic improvement in her condition.

"After one week on Dr. Levine's exercise program, I was out of my wheelchair for short durations," she said. "After two months, I was able to walk for 30 minutes with no assistance. I haven't stopped moving since."

In the spring of 2011, Knight was able to walk across the stage - completely unassisted - at her high school graduation ceremony, and even gave the commencement address. Grateful for Levine's work, Knight and her classmates organized a school fundraiser during National Heart Month to support POTS research at the IEEM.

"Without the help of Dr. Levine's research, I don't know how long it would have taken me to recover, if ever," she explained. "I don't know if I would be in a position to further my education by attending college this fall."

Note: This feature excerpted from the Fall 2011 Perspectives newsletter, published by the Texas Health Research & Education Institute.

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