Experiencing shortness of breath while bending forward, termed “bendopnea,” could be an indicator of heart failure, according to researchers at the University of Texas Southwestern Medical Center in Dallas in a study published in the Journal of the American College of Cardiology.

Jennifer T. Thibodeau, MD, MSc, and colleagues evaluated 102 patients referred to the University of Texas Southwestern Medical Center for right heart catheterization. They conducted a history and physical on each patient prior to the procedure, which included an assessment for bendopnea. To test for bendopnea, participants sat in a chair and bent forward at the waist as if to put on shoes or socks. A study investigator timed the duration to onset of shortness of breath. The researchers defined bendopnea as specifically shortness of breath, not lightheadedness or fullness, that occurred within 30 seconds of bending.

A subset of 46 patients also underwent hemodynamic evaluation while sitting upright and while bending forward from a seated position. The investigators classified patients into one of four hemodynamic profiles based on left ventricular filling pressures and cardiac index (CI). Those with profile A were “’warm and dry’” with a CI of greater than 2.2 l/min/m² and a pulmonary capillary wedge pressure (PCWP) of less than 22 mm Hg; those with profile B were “’warm and wet’” with a CI of greater than 2.2 l/min/m² and a PCWP of 22 mm Hg or higher; those with profile C were “cold and wet’” with a CI of less than or equal to 2.2 l/min/m² and a PCWP of 22 mm Hg or higher; and those with profile L were “’cold and dry’” with a CI of less than or equal to 2.2 l/min/m² and a PCWP of less than 22.

Of the 102 patients, 29 experienced bendopnea (28 percent) and the average time to onset of eight seconds. Participants with bendopnea had higher right atrial pressure (RAP) while lying down and PCWP than those without bendopnea. CI, however, was similar. RAP and PCWP increased in groups when bending, but CI did not change.

Participants with bendopnea had more than a three-fold higher frequency than participants without bendopnea of having a supine hemodynamic profile consisting of a PCWP higher than 22 mm Hg and a CI less than 2.2 l/min/m² (55 percent vs. 16 percent).

The authors noted that their study was the first to identify bendopnea as a symptom of heart failure. The symptom is mediated by increasing filling pressures while bending when those pressures are already high, especially if CI is low.

While they acknowledged that additional studies should determine how frequent bendopnea is in the general heart failure population, they argued clinicians should be aware of this symptom to “improve their noninvasiveness assessment of hemodynamics in patients with heart failure,” they wrote.

This study was published in the February issue of the journal.