Researchers identify 'bendopnea' as new symptom for heart failure
If a patient with heart failure experiences shortness of breath as he or she leans forward to tie a shoelace or put on a sock, it might be an overlooked sign that their disease is advancing, a new study finds. Researchers coined the term “bendopnea" to describe the phenomenon, and say awareness of the symptom can provide physicians a simple and noninvasive means of diagnosing excessive fluid retention in patients with the disease.
About 5.1 million people in the United States have heart failure and about half of those who develop the condition die within five years of diagnosis, according to the Centers for Disease Control and Prevention. Shortness of breath is one of the common symptoms, but cardiologists at the University of Texas Southwestern Medical Center in Dallas noticed that several of their heart failure patients described shortness of breath specifically while bending forward. They decided to investigate further.
“Some patients thought they were short of breath because they were out of shape or overweight, but we wondered if there was something more to it,” said study author Dr. Jennifer Thibodeau, assistant professor of internal medicine in the UT Southwestern Medical Center division of cardiology.
She and a team of UT researchers conducted a small, observational study of patients with systolic heart failure who had been referred for right heart catheterization at their medical center between June 2010 and May 2012.
To determine whether the patients actually had bendopnea—a symptom the investigators defined as shortness of breath within 30 seconds of bending forward—the patients were instructed to lean forward at the waist while seated, and a researcher timed how quickly the patient reported breathing problems. The symptom was present in 29 of the 102 patients, often within as little as eight seconds. These patients were also more likely to have other symptoms of advanced disease.
“The results confirmed what we were already seeing in our patients,” Thibodeau said in an e-mail. Patients with bendopnea had too much fluid in their bodies, causing elevated pressure, and when they leaned forward the pressure increased even further.
“For physicians, sometimes it can be difficult to assess whether a patient has fluid retention, and the assessment of bendopnea can be an additional tool that is used to help in the evaluation,” she said. The findings were published this week in the journal of the American College of Cardiology.
“It's a brilliant piece of work,” said American Heart Association spokesman Dr. Clyde Yancy, a cardiology professor at Northwestern University's Feinberg School of Medicine in Chicago. He did not work on the study, but is formerly part of the group that made the new observation.
“Paying attention to what patients say can teach us what we need to know,” he said, citing Sir William Osler, a Canadian physician famous for the saying: "Listen to your patient, he is telling you the diagnosis."
Researchers plan to further investigate bendopnea's correlation with other markers of disease severity and evaluate it in other patient populations, such as those with pulmonary hypertension. Though the study is small and the data should be replicated, Yancy says the research is a promising tool which physicians can use to understand which patients with heart failure are sicker.
“Clearly when we can add another tool … we improve our ability to take care of patients,” he said.
That sentiment was shared in an editorial, co-authored by Dr. Anju Nohria and Dr. Lynne Warner Stevenson of Brigham and Women's Hospital in Boston. They write that the tool can be used as a simple bedside test to identify patients who may not otherwise show symptoms. Like, Yancy, though, they were most impressed with the researchers' keen observations from simply listening to patients.
“Even when our patients cannot be cured,” they wrote, “listening may help us render them able to put on their own shoes again.”
Regarding how the term—bendopnea—was selected, Thibodeau said, “We wanted a name that would be immediately recognizable and descriptive of our new symptom,” she said. “We have found that doctors (and even patients) who hear the term for the first time know exactly what it means.”
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