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Updated: Mar 31, 2026
Inspiratory Muscle Training as an Adjunct to the Treatment of Weaning Failure in Critically Ill Patients: A Practical Guide
Published on: January 30, 2026
Inspiratory Muscle Weakness is Associated With Exercise Intolerance in Patients With Heart Failure With Preserved
Kensaku Yamada1, Yoshiharu Kinugasa1, Takeshi Sota1
1Division of Cardiovascular Medicine, Department of Molecular Medicine and Therapeutics, Faculty of Medicine, Tottori University, Yonago, Japan.
Background:
The relationship between inspiratory muscle weakness (IMW) and exercise intolerance in patients with heart failure with preserved ejection fraction (HFpEF) remains unestablished.
Methods And Results:
The present study enrolled 40 patients with HFpEF (EF ≥45%). IMW was defined as maximum inspiratory pressure <70% normal predicted values. The function of the diaphragm was assessed by means of ultrasound measurement of muscle thickening of the diaphragm. IMW was prevalent in 27.5% of patients. Patients with IMW had significantly lower vital capacity relative to normal predicted values (%VC), lower knee extensor muscle strength in relation to body weight (%KEMS), poorer nutritional status as assessed by means of the Geriatric Nutritional Risk Index, and shorter 6-minute walk distance (6MWD) compared with patients without IMW (all P < .05). Impaired diaphragm muscle thickening at end-inspiration (median value < 3.9 mm) was significantly associated with a high prevalence of IMW and reduced 6MWD (all P < .05). Subgroup analysis showed that IMW was accompanied by a further decrease in 6MWD in patients with restrictive pulmonary dysfunction (%VC <80%) or lower-limb muscle weakness (median %KEMS <30%; all P < .05).
Conclusions:
IMW is associated with exercise intolerance in patients with HFpEF.
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