Study provides new insight into different forms of heart failure

Using a novel noninvasive technique, a team of researchers led by a professor at the University of Texas Arlington's College of Nursing and Health Innovation has been able to measure oxygen consumption in the legs of heart failure patients, providing additional insight into this syndrome.

The results of the study were published in the Journal PLOS ONE and could bode well for the future treatment of patients. Mark Haykowsky, the college's Moritz Chair of Gerontology Nursing Research, was the senior author of the journal article.

For the study, the researchers recruited 10 older heart failure patients with either big, dilated hearts that do not pump blood well or big, stiff hearts that do not relax properly after exercise. Both types of patients have high mortality rates.

Typically, measuring leg blood flow and oxygen extraction and consumption is a tedious process. It requires the insertion of a catheter into an artery and vein.

The team developed a technique to measure leg blood flow and oxygen consumption using magnetic resonance imagining technology. Following four minutes of constant knee extension exercise, the researchers measured leg oxygen consumption and its determinants during the recovery period.

"We wanted to see if these two groups differ in their leg oxygen consumption in the recovery period after exercise, and if so, why this occurred," said Haykowsky.

Their measurements showed that there was indeed a difference between the two groups. Leg blood flow and oxygen uptake recovery took longer in patients with dilated hearts.

"This study is an important breakthrough because we were able to distinguish between different groups of heart failure patients," said Haykowsky. "This could have important implications for exercise rehabilitation for heart failure patients," he said. "If we're able to differentiate between these heart failure groups then in the future we could target therapies aimed at increasing blood flow to their muscles and improve their exercise capacity. Fatigue and exercise intolerance are cardinal features in heart failure."

Anne Bavier, dean of the College of Nursing and Health Innovation, said this study further positions UTA as an innovative leader in the battle against heart disease and could bring hope to millions of people.

"This study is a critically important weapon in the battle against this ailment," said Bavier. "It suggests that there are different underlying pathologies among groups of patients with various forms of heart failure and it opens up the possibility of therapies specifically targeted at these groups. "

Haykowsky is one of several faculty members within the College of Nursing and Health Innovation working to tackle a variety of cardiovascular ailments. Michael Nelson, an assistant professor, is studying the root causes of a frequently misdiagnosed heart condition that affects blood vessels in women's hearts. Associate Professor Matthew Brothers studies vascular function in populations with high risks of cardiovascular disease. Paul Fadel, a professor and the college's associate dean for research, is a respected expert in neural cardio-vascular control in health and disease. Improving health and the human condition is one of the four main themes of UTA's Strategic Plan 2020 Bold Solutions|Global Impact.

Haykowsky said he and fellow researchers plan to conduct future studies using this technique with a larger group of heart failure patients.

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UTA's College of Nursing and Health Innovation is a National League for Nursing Center of Excellence and encompasses one of the nation's largest and most successful nursing schools and a renowned kinesiology program offering degrees in exercise science, kinesiology, athletic training and an undergraduate track in public health. The College is the largest producer of registered nurses in Texas and a leader in the use of online platforms and simulation technology to help more students achieve nursing degrees. U.S. News & World Report ranks the Master of Science in Nursing program and the online Master of Science in Nursing degree among the best in the country. The College's highly regarded faculty is dedicated to advancing health and the human condition and investigates a wide range of topics in basic science, human performance and clinical conditions.

The University of Texas at Arlington is a Carnegie Research-1 "highest research activity" institution. With a projected global enrollment of close to 57,000, UTA is one of the largest institutions in the state of Texas. Guided by its Strategic Plan 2020 Bold Solutions|Global Impact, UTA fosters interdisciplinary research and education within four broad themes: health and the human condition, sustainable urban communities, global environmental impact, and data-driven discovery. UTA was recently cited by U.S. News & World Report as having the second lowest average student debt among U.S. universities. U.S. News & World Report ranks UTA fifth in the nation for undergraduate diversity. The University is a Hispanic-Serving Institution and is ranked as the top four-year college in Texas for veterans on Military Times' 2017 Best for Vets list.