Higher Work of Breathing During Exercise in Heart Failure With Preserved Ejection Fraction.

Background: It is unknown if pulmonary alterations in heart failure with preserved ejection fraction (HFpEF) impact respiratory mechanics during exercise.

Research Question: Are the operating lung volumes, work of breathing (Wb), and power of breathing (Pb) abnormal in patients with HFpEF during exercise?

Study Design And Methods: Patients with HFpEF (n = 8; median age, 71 years [interquartile range (IQR), 66-80 years]) and control participants (n = 9; median age, 68 years [IQR, 64-74 years]) performed incremental cycling to volitional exhaustion. Esophageal pressure, end-expiratory lung volume (EELV), inspiratory lung volume (EILV), and ventilatory variables were compared at similar absolute (30 and 50 L/min) and relative (45% of peak, 70% of peak, and 100% of peak) minute ventilation (V.