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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
Inspiratory muscle high endurance protocol increases heart rate variability in myocardial revascularization patients
Scientific title
Heart rate variability response during muscle high endurance protocol in myocardial revascularization patients
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
myocardial revascularization patients 3467 0
Condition category
Condition code
Cardiovascular 3655 3655 0 0
Coronary heart disease

Study type
Description of intervention(s) / exposure
First, the voluntaries were submitted to anthropometric evaluation constituted by height and weight measurements (utilizing a stadiometer and a calibrated balance). On the same day, and in just a single session the respiratory muscle strength was evaluated by measurement of maximal inspiratory and expiratory pressure values, utilizing an aneroid manovacuometer. For this, each maneuver it was made at three repetitions with an interval of one minute between each repetition.The forced inspiratory maneuver was performed from residual volume and the forced expiratory maneuver was performed from total pulmonary capacity.
After determination of the maximum respiratory pressures, an inspiratory muscle endurance protocol was applied and consisted of effort at two pressure levels: 60 and 80% of maximal inspiratory pressure. The loads were applied in a random order that had been chosen before the experiment.
During the protocol the patient remained seated in a chair, using a nose clip and performed inspiratory effort utilizing the manovacuometer which had previously shown in the visor the value that corresponded to the individual’s pressure percentage of maximal inspiratory pressure (60 or 80%). Each effort level was performed for four minutes and the patient was oriented to make an inspiratory effort and maintain the equipment indicator on the demarcated line, which corresponded to the percentage being tested, for two seconds followed by expiration through the mouth for three seconds and which completed a total of 12 respiratory cycles per minute. To ensure that the maneuver was performed correctly and at the correct times for inspiration and expiration as previously instructed, one of the evaluators used a chronometer to give verbal commands to the patient. The protocol was made in just one day.
Intervention code [1] 2506 0
Intervention code [2] 2789 0
Other interventions
Comparator / control treatment
There are no control group
Control group

Primary outcome [1] 3779 0
The respiratory muscle strength was measured by an aneroid manovacuometer
Timepoint [1] 3779 0
2 minutes between each load (60 and 80% maximal inspiratory pressure)
Primary outcome [2] 4081 0
The heart rate was measured using an electrocardiography
Timepoint [2] 4081 0
During the maximum inspiratory pressure measurement
Secondary outcome [1] 6380 0
To compare the maximal respiratory pressure with the predicted values. After the maximal inspiratory and expiratory pressures measurement were taken for each patient using an aneroid manovacuometer, these values were compared to the predicted values for the Brazilian population according to Neder et al. The predicted values were calculated for each patient utilizing the following formulas: MIP= -0.80 (age) + 119.7 + 0.48 (weight) and MEP = -0.81 (age) + 165.3.
Timepoint [1] 6380 0
after the subject did three repetitions of each maneuver with an interval of one minute between each repetition.

Key inclusion criteria
Postoperative myocardial revascularization coronary patients who had undergone surgery a minimum of 12 months year All patients participants in a cardiovascular rehabilitation program for at least 12 months. Classified as eutrophic (body mass index from 18.5 to 24.9 kg/m2) or overweight (body mass index from 25 to 29.9 kg/m2).
Minimum age
55 Years
Maximum age
70 Years
Can healthy volunteers participate?
Key exclusion criteria
smokers, pacemakers, complex arrhythmias, left ventricular dysfunctions, neurological and/or respiratory disturbances and had no visible alterations in thoracic and/our abdominal mobility, or accentuated structural deviations in the spine that might alter the dynamic respiratory.

Study design
Purpose of the study
Educational / counselling / training
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Who is / are masked / blinded?

Intervention assignment
Single group
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 770 0
State/province [1] 770 0
Sao Carlos, Sao Paulo

Funding & Sponsors
Funding source category [1] 3017 0
Name [1] 3017 0
Programa Unificado de Iniciacao Cientifica (PUIC)
Address [1] 3017 0
Rodovia Washington Luis (SP-310), km 235
Sao Carlos - Sao Paulo
Country [1] 3017 0
Primary sponsor type
Universidade Federal de São Carlos
Rodovia Washington Luis (SP-310), km 235
Sao Carlos - Sao Paulo
Secondary sponsor category [1] 2725 0
Name [1] 2725 0
Audrey Borghi e Silva
Address [1] 2725 0
Laboratorio de Fisioterapia Cardiorrespiratoria, NUPEF, Rodovia Washington Luis (SP-310), km 235
Sao Carlos - Sao Paulo
Country [1] 2725 0

Ethics approval
Ethics application status

Brief summary
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 28331 0
Address 28331 0
Country 28331 0
Phone 28331 0
Fax 28331 0
Email 28331 0
Contact person for public queries
Name 11488 0
Rodrigo Polaquini Simões
Address 11488 0
Laboratorio de Fisioterapia Cardiorrespiratoria, NUPEF, Rodovia Washington Luis (SP-310), km 235
Sao Carlos - Sao Paulo
Country 11488 0
Phone 11488 0
(16) 3375-2540
Fax 11488 0
(16) 3375-2540
Email 11488 0
Contact person for scientific queries
Name 2416 0
Rodrigo Polaquini Simões
Address 2416 0
Laboratorio de Fisioterapia Cardiorrespiratoria, NUPEF, Rodovia Washington Luis (SP-310), km 235
Sao Carlos - Sao Paulo
Country 2416 0
Phone 2416 0
(16) 3375-2540
Fax 2416 0
(16) 3375-2540
Email 2416 0

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary