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.
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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
SINGLE
Enrollment
14
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
Otto Wagner Spital, Dep. of Respiratory and Critical Care Medicine
Vienna, Austria
E/A-ratio (absolute change between tidal breathing and smallest stenosis)
E/A-ratio will be measured by transthoracic echocardiography (Vivid S9, general electric healthcare, Fairfield, USA) according to the valid standards of The European Association of Echocardiography. This parameter represents the left-ventricular diastolic function.
Time frame: At the end of each cycle - tidal breathing as well as hyperinflation-intervention (each cycle is at least 90 seconds).
E/E'-ratio
E/E'-ratio will be measured by transthoracic echocardiography (Vivid S9, general electric healthcare, Fairfield, USA) according to the valid standards of The European Association of Echocardiography. This parameter represents the left-ventricular diastolic function.
Time frame: At the end of each cycle - tidal breathing as well as hyperinflation-intervention (each cycle is at least 90 seconds).
deceleration time of the E-wave transmitral (msec)
deceleration time will be measured by transthoracic echocardiography (Vivid S9, general electric healthcare, Fairfield, USA) according to the valid standards of The European Association of Echocardiography. This parameter represents the left-ventricular diastolic function.
Time frame: At the end of each cycle - tidal breathing as well as hyperinflation-intervention (each cycle is at least 90 seconds).
Maximal diastolic transtricuspid flow (m/sec)
Maximal diastolic transtricuspid flow will be measured by transthoracic echocardiography (Vivid S9, general electric healthcare, Fairfield, USA) according to the valid standards of The European Association of Echocardiography. This parameter represents the left-ventricular diastolic function.
Time frame: At the end of each cycle - tidal breathing as well as hyperinflation-intervention (each cycle is at least 90 seconds).
Maximal late-systolic velocity of the lateral tricuspid valve in Tissue Doppler Imaging (cm/sec)
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Maximal late-systolic velocity will be measured by transthoracic echocardiography (Vivid S9, general electric healthcare, Fairfield, USA) according to the valid standards of The European Association of Echocardiography. This parameter represents the left-ventricular diastolic function.
Time frame: At the end of each cycle - tidal breathing as well as hyperinflation-intervention (each cycle is at least 90 seconds).
Inspiratory Capacity
Inspiratory Capacity will be measured with a pneumotachograph (VenThor D-22/5B, ThorMedical, Budapest, Hungary). It represents the extent of dynamic hyperinflation.
Time frame: At the end of each cycle - tidal breathing as well as hyperinflation-intervention (each cycle is at least 90 seconds).
Dynamic Intrinsic Positive Endexpiratory Pressure:
To objectify the dynamic hyperinflation in addition to the Inspiratory Capacity, the Intrinsic Positive Endexpiratory Pressure will be measured by the invasive application of an esophageal balloon catheter (ICU-Lab, Kleistek Engineering, Bari, Italy).
Time frame: During each entire cycle - tidal breathing as well as hyperinflation-intervention (each cycle is at least 90 seconds).