Hans-Joachim Kabitz1, Anja Schwoerer1, Hinrich-Cordt Bremer1, Florian Sonntag1,

Stephan Walterspacher1, David Walker1, Vanessa Schaefer2, Nicola Ehlken2,

Gerd Staehler3, Michael Halank4, Hans Klose5, Hossein A. Ghofrani6,

Marius M. Hoeper7, Ekkehard Gruenig2 and Wolfram Windisch1

1Department of Pneumology, University Hospital Freiburg, Germany

2Department of Cardiology and Pneumology, University Hospital Heidelberg, Germany3Department of Pneumology and Cardiology, Loewenstein Hospital Loewenstein, Germany

4Department of Internal Medicine I, University Hospital Dresden, GermanyDepartments of Pneumology, University Hospitals Hamburg-Eppendorf5 and Giessen6, Germany

7Department of Pneumology, Hannover Medical School, Germany

Impairment of Respiratory Muscle Function

in Pulmonary Hypertension

Killianstraße 579106 Freiburg, GermanyTel. +49/761-270-3707

hans-joachim.kabitz@uniklinik-freiburg.de

Respiratory muscle impairment in chronic left heart failureInspiratory muscle strength independent predictor of prognosis

Dyspnea on exertion and fatigue most common symptomsIn part be explained by impaired respiratory muscle function

Respiratory muscle impairment in pulmonary hypertension ?Assessment of ventilatory characteristics and muscle strength

Clinical impact of respiratory muscle impairment ?Exercise capacity vs muscle strength

Rationale

Methods I

Participants matched for age and Body-Mass-Index (BMI)

Pulmonary hypertension patients n=31

Control subjects n=31

PH patients Controls p-value

Age [years] 57 ± 14 55 ± 12 NS

BMI [kg/m²] 26 ± 6 27 ± 5 NS

25 PAH* 6 CTEPH#

20 11

20 11

*Pulmonary Arterial Hypertension#Chronic Thrombo-Embolic Pulmonary Hypertension

Lung function analysis

Respiratory muscle testing

- Ventilatory characteristics

P0.1 inspiratory mouth occlusion pressure after 0.1 s

P0.1/PImax respiratory capacity

P0.1*ti/VT specific inspiratory impedance

- Respiratory muscle strength

PImax maximal inspiratory mouth occlusion pressure

PEmax maximal expiratory mouth occlusion pressure

Sn P sniff pressures

Tw P twitch pressures during BAMPS*

*Bilateral Anterior Magnetic Phrenic Nerve Stimulation

Volitional

Non-Volitional

Volitional

Methods II

Methods III

Bilateral Anterior Magnetic Phrenic Nerve Stimulation

- BAMPS -Tw Pdi = Tw Pes – Tw Pga

Phrenic Nerve

Results I

PH patients Controls p-value

P0.1 [kPa] 0.28 ± 0.15 0.23 ± 0.10 NS

P0.1/PImax [%] 6.3 ± 7.1 3.3 ± 1.8 NS

P0.1*ti/VT [kPa*s/l] 0.50 ± 0.20 0.52 ± 0.15 NS

Ventilatory characteristics

P0.1 inspiratory mouth occlusion pressure after 0.1 s

P0.1/PImax respiratory capacity

P0.1*ti/VT specific inspiratory impedance

Results II

Volitional tests on respiratory muscle strength

Results III

Non-volitional tests on respiratory muscle strength

Results IV

Regression analysis PImax vs 6MWD

Comparable ventilatory characteristicsCentral drive, capacity and load

Substantially reduced respiratory muscle strength in PHReduction in all volitional tests

Even more pronounced considering non-volitional tests

Inspiratory muscle strength related to 6MWDPotential predictor of prognosis in PH

Respiratory muscle training in PH patients

Enhanced exercise tolerance, outcome improvement

Summary

hank you

for your attention !

Hans-Joachim Kabitz

University Hospital Freiburg, GermanyDepartment of PneumologyKillianstraße 579106 FreiburgTel. +49/761-270-3707hans-joachim.kabitz@uniklinik-freiburg.de

Impairment of Respiratory Muscle Function

in Pulmonary Hypertension

Kabitz et al. 2007; Clinical Science (London); in press

www.clinsci.org