Bendopnea — What Is It and What’s Its Significance?
Abstract & Commentary
By Harold L. Karpman, MD, FACC, FACP
Clinical Professor of Medicine, UCLA School of Medicine
Dr. Karpman reports no financial relationships relevant to this field of study.
Synopsis: Bendopnea, which is defined as shortness of breath when bending over, has been found to be a dominant symptom in patients with heart failure. It appears to be caused by a further increase in filling pressures when bending over in patients with heart failure, especially when filling pressures are already high and the cardiac index is reduced.
Source: Thibodeau JT, et al. Characterization of a novel symptom of advanced heart failure: Bendopnea. JACC Heart Fail 2014;2:24-31.
Shortness of breath may occur quite frequently at
rest, but more commonly it tends to occur with exercise. It is a dominant symptom in patients with heart failure (HF) and is usually subclassified based on the nature of the activity that provokes its onset. Thibodeau and colleagues coined the term "bendopnea" to describe the many patients who develop shortness of breath specifically when bending forward, such as when putting on their shoes and socks.1 They found the symptom to occur more frequently in patients with HF. To determine the mechanism and clinical implications of this symptom, they conducted a prospective study of 102 patients with systolic HF referred for right-heart catheterization to determine the frequency of occurrence of bendopnea.
Bendopnea was found to occur in 29 of the 102 research subjects with a median time to onset of 8 seconds. These patients were found to have higher supine right atrial pressure (RAP) and pulmonary capillary wedge pressure (PCWP) than did those subjects who did not develop bendopnea. RAPs and PCWPs increased comparably in subjects both with and without bendopnea when bending but the cardiac index (CI) did not change. They concluded that bendopnea which occurred in patients with HF was mediated by a further increase in the high resting filling pressures found in these patients precipitated by bending, especially if the CI was reduced.
The intent of this study was to determine the pathophysiological basis of bendopnea. Thibodeau et al found the symptom not to be related to body habitus. Although the body mass index was generally higher in the bendopnea patients, there were no significant differences in waist circumference or waste/hip ratio suggesting that increased abdominal girth was not the primary cause of the symptom. The preliminary data suggested that during bending, the intrathoracic pressure increases, leading to a further increase in ventricular filling pressures, and the subjects with bendopnea were more likely to reach a higher threshold pressure that resulted in the observed increased shortness of breath. Pulmonary congestion has been demonstrated to portend a poor prognosis2-7 with a significantly increased risk of all-cause mortality, an increased risk for hospitalization for HF, and death from pump failure.3 It should be carefully noted that the number of subjects enrolled in the study was relatively small and very select because they already had known systolic HF and had been referred for right-heart catheterization. It was also difficult to compare other symptoms of HF with the occurrence of bendopnea because the other symptoms were solely dependent on patient recall over the week prior to the heart catheterization. Finally, factors other than elevated left ventricular filling pressure may also contribute to the symptom since some patients with bendopnea did not have an elevated PCWP.
Although the results of this very small preliminary study suggest the pathophysiological reasons why patients develop bendopnea, additional and larger well-controlled studies need to be performed to determine its prevalence in the general HF population. It is hoped that awareness of the symptom by physicians will improve their noninvasive assessment of the hemodynamics in patients who complain of bendopnea whether they have HF or not.
In summary, clinicians should be aware that patients presenting with bendopnea may be suffering from chronic or acute HF and should be evaluated and treated appropriately.
- Thibodeau JT, et al. Characterization of a novel symptom of advanced heart failure: Bendopnea. JACC Heart Fail 2014;2:24-31.
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