Effects of Dynamic Hyperinflation on the Left-ventricular Diastolic Function in Healthy Male Subjects
Condition: Pulmonary Disease, Chronic Obstructive
MeSH terms: Lung Diseases; Pulmonary Disease, Chronic Obstructive
Study type: Interventional

Summary: 
      The aim of this study is to identify whether actively induced dynamic hyperinflation can
      cause left-ventricular diastolic dysfunction in healthy male subjects in order to explore the
      mechanisms of developing cardiac dysfunctions in patients with COPD.
    

Detailed description: 
      Cardiovascular diseases, especially left-ventricular diastolic dysfunction, are among the
      most frequent reasons for morbidity and mortality in patients with chronic obstructive
      pulmonary disease (COPD).

      Dynamic hyperinflation is one of the expected pathophysiological mechanisms in the
      multifactorial genesis of this left-ventricular diastolic dysfunction in patients with COPD.

      The novel concept of Expiratory Stenosis Breathing (ESB) is based on the method of
      Metronome-Paced Tachypnea (MPT) of Cooper et al. Therefore the investigators use a metronome
      to indicate a specific breathing frequency (BF) and the relation of inspiration : expiration
      (I : E) in order to let subjects hyperinflate.

      Subjects get split into two groups each hyperinflating three times for 90sec by one of the
      two methods before doing a cross-over and switch groups to do the same in the other group. At
      the end of the 90sec there is a measurement of the Inspiratory Capacity (IC) and an
      echocardiography in order to objectify dynamic hyperinflation respectively the change in
      diastolic function.

      During ESB participants hyperinflate with a BF - 30/min and a I : E - 1 : 3. In addition they
      have to breathe through an expiratory-effective stenosis (3, 2 and 1,5mm) on the mouthpiece
      of the pneumotachograph to simulate the collapsing airways in COPD-patients. In contrast,
      during MPT subjects hyperinflate with a BF - 40/min, I : E - 1 : 1; BF - 40/min, I : E - 1 :
      2; BF - 30/min, I : E - 1 : 2.

      During the whole trial investigators measure Intrinsic Positive Endexpiratory Pressure
      (PEEPi) in order to objectify the dynamic hyperinflation more significantly.

      The primary goal of this study is to assess if actively induced dynamic hyperinflation can
      affect diastolic function of the left ventricle.

      Furthermore a correlation between the extent of dynamic hyperinflation and diastolic
      dysfunction should be quantified.

      In addition measurement of PEEPi should validate the method of Metronome-paced Tachypnea
      (MPT) because the investigators hypothesize that this method does not simulate the
      pathophysiological circumstances in patients with COPD sufficiently.
    

Intervention name(s): Metronome-paced tachypnea; Expiratory-stenosis breathing
Intervention type(s): Procedure; Procedure
Intervention description(s): three cycles: breathing frequency (BF) - 40/min, inspiration : expiration (I : E) - 1 : 1; BF - 40/min, I : E - 1 : 2; BF - 30/min, I : E - 1 : 2; three cycles: BF - /min, I : E - 1 : 3; stenosis: 3mm; 2mm; 1,5mm
Other intervention name(s): MPT; ESB
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Basic Science
Keywords: dynamic hyperinflation; diastolic dysfunction; COPD; Chronic Obstructive Pulmonary Disease; Metronome-paced Tachypnea; Expiratory-stenosis Breathing