Optoelectronic Pletysmography and Diaphragmatic Thickness in Heart Failure Patients

Study Overview
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Brief Summary
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The investigators aimed to evaluate the effects of cardiomegaly associated with inspiratory muscle weakness on tricompartmental distribution of chest wall volumes, on the thickness of the right hemidiaphragm and on the contraction speed of the respiratory muscles. As method of the present research, a pilot cross-sectional study was conducted with fourteen (14) patients with heart failure, functional class II and III, clinically stable, with cardiomegaly. Two groups were formed: one group with inspiratory muscle weakness (WG) (maximal inspiratory pressure - MIP <70% predicted MIP) and a control group without weakness (CG). The pulmonary and respiratory muscle functions were assessed by spirometry and manometer, respectively. Before and after maximal exercise test, optoelectronic plethysmography was performed to evaluate the distribution of volumes, the kinematics and the contraction speed of chest wall muscles. The high-resolution ultrasonography was also used before and after the maximum test for obtaining diaphragmatic thickness

Official Title
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Effect of Cardiomegaly Associated With Inspiratory Muscle Weakness on Diaphragm Thickness and Chest Wall Volume Distribution in Patients With Heart Failure

Conditions
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Heart Failure

Intervention / Treatment
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* Other: Maximal exercise ramp test


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Both sexes, 18-60 years; Functional Class II-III according to the New York Heart Association; Echocardiography of the last six months showing showing left ventricular ejection fraction (LVEF) ≤ 45% measured by Teichholz method; Echocardiography the last six months showing cardiac hypertrophy (Diameter of Left Ventricular Diastolic (LVDD)> 54 mm, diameter of Systolic Left Ventricular (LVSD)> 34mm) 30 measured by Teichholz method; Optimized by the medical point of view and Clinical stability Exclusion Criteria: Unstable angina; myocardial infarction or heart surgery up to three months before the survey; Orthopedic diseases, infectious or chronic metabolic diseases; The relation between forced expiratory volume in the first second and forced vital capacity (FEV1 / FVC) <70% of predicted characterizing obstructive respiratory disorder and Active smokers.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Weakness Group (WG)<br>Patients with heart failure and a maximum inspiratory pressure (MIP) <70% of predicted MIP to age, considered as inspiratory muscle weakness. Following the recruitment process, these volunteers will be evaluated by spirometry and manovacuometry. Afterwards, volunteers will be also assessed in a maximal exercise ramp test. Before and after the ramp test, the optoelectronic pletysmography will be performed to analyse the chest wall tricompartmental distribution and the shortening velocities of rib cages muscles. Also a high-definition ultrasonography will be performed to measure the right diaphragmatic cupule thickness | Other: Maximal exercise ramp test<br>* The maximal exercise ramp test, symptom-limited, performed by all patients in the study was performed based on treadmill ramp protocol through ErgoPC Elite® software associated with 12-channels electrocardiogram. Respiratory variables were obtained in standard conditions of temperature, pressure and humidity (StPD), breath-by-breath, with the patient breathing through a face mask without leaks coupled to gas analyzer (Cortex - Metamax 3B, Germany).To ensure that patients reached maximum effort during the examination, only the tests which patients obtain a respiratory exchange ratio (RR) ≥1.1 were accepted .<br>|
| Control group (CG)<br>Patients with heart failure and do not have a maximum inspiratory pressure (MIP) > 70% of predicted MIP to age, considered as inspiratory muscle weakness. Following the recruitment process, these volunteers will be evaluated by spirometry and manovacuometry. Afterwards, volunteers will be also assessed in a maximal exercise ramp test. Before and after the ramp test, the optoelectronic pletysmography will be performed to analyse the chest wall tricompartmental distribution and the shortening velocities of rib cages muscles. Also a high-definition ultrasonography will be performed to measure the right diaphragmatic cupule thickness | Other: Maximal exercise ramp test<br>* The maximal exercise ramp test, symptom-limited, performed by all patients in the study was performed based on treadmill ramp protocol through ErgoPC Elite® software associated with 12-channels electrocardiogram. Respiratory variables were obtained in standard conditions of temperature, pressure and humidity (StPD), breath-by-breath, with the patient breathing through a face mask without leaks coupled to gas analyzer (Cortex - Metamax 3B, Germany).To ensure that patients reached maximum effort during the examination, only the tests which patients obtain a respiratory exchange ratio (RR) ≥1.1 were accepted .<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diaphragmatic thickness | A high-definition ultrasound in the the B mode with linear transducer of 7.5 megahertz was used to measure diaphragmatic thickness. In the lateral decubitus position, the transducer was positioned perpendicular to the chest, between the eighth and ninth intercostal spaces between the right anterior and medium axillary lines. Diaphragm was identified by two hyperechoic (bright) lines parallel to the pleural and parietal membranes respectively. The measurement of diaphragm thickness was held from the middle of the pleural line to the middle of peritoneal. The average of 3 final measures taken at the apposition zone obtained: at functional residual capacity (thickness of the relaxed diaphragm - Erel) at the end of the total lung capacity (thickness of the diaphragm contracted - Econt) and during a maximal inspiratory pressure maneuver from functional residual capacity. | 30 minutes | 
| Chest Wall tricompartmental volumes | The images generated by the triangulation of the infra-red light reflected by 89 markers placed over volunteers' chest walls and captured by 8 cameras allows the visualization of the same thoraxes as entire structure and in its own tricompartmental division: pulmonary rib cage (RCp), abdominal rib age (RCab) and abdomen (AB). Each compartment can be evaluated in terms of their volume variation across the recorded respiratory cycle. | 30 minutes |