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.
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
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
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
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."
feature excerpted from the Fall 2011 Perspectives
newsletter, published by the Texas Health Research &