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Trial registered on ANZCTR


Registration number
ACTRN12618001812280
Ethics application status
Approved
Date submitted
9/10/2018
Date registered
7/11/2018
Date last updated
5/11/2019
Date data sharing statement initially provided
7/11/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
Holter monitoring to assess QT interval and heart rate variability in women diagnosed previously with broken heart syndrome
Scientific title
24 hour holter ECG monitoring to measure QT interval and autonomic function in patients with a history of takotsubo syndrome using voluntary hyperventilation
Secondary ID [1] 296161 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Takotsubo Syndrome 309897 0
Condition category
Condition code
Cardiovascular 308684 308684 0 0
Other cardiovascular diseases

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Breathing exercises will be performed with the participant seated.

3 minutes of voluntary hyperventilation: the participant will be asked to consciously breathe deeper and faster for three minutes. Hyperventilation will be performed in a supervised setting. It is an autonomic nervous system stimulus that does not involve physical activity, the patient is seated. We are using it in this study in this manner as we will be able to accurately know the timing and can therefore correlate any autonomic changes seen on the ECG recording. Voluntary hyperventilation can cause a feeling of mild anxiety. The mild anxiety that may result is at a level similar to what may be encountered in normal everyday life. There is no specific risk from this. The supervisor will discontinue the hyperventilation if this develops. Hyperventilation may also cause a dry mouth as a direct effect of increased air flow. The supervisor will discontinue the exercise if the participant notes a dry mouth. Drinking water will also be available.

The ECG will be recorded continuously for 24 hours from the start of the intervention with a Holter monitor. The monitor will be fitted by one of the study authors trained in fitting the monitor. The patient will be phoned three times during the 24 hour period to ensure adherence and to take a 20 question emotional survey. The monitor is worn on two occasions with a one week washout period between.
Intervention code [1] 312573 0
Other interventions
Comparator / control treatment
3 minutes of controlled diaphragmatic breathing will serve as the control. It should not result in autonomic nervous system activation and from the patient perspective will be a similar exercise to the hyperventilation. Instructions to the patient are as follows:
• Take a long, slow breath in through your nose, first filling your lower lungs, then your upper lungs.
• Hold your breath to the count of "three."
• Exhale slowly through pursed lips, while you relax the muscles in your face, jaw, shoulders, and stomach.

There are no specific risks associated with three minutes of controlled diaphragmatic breathing.
Control group
Active

Outcomes
Primary outcome [1] 307656 0
Acute QT interval changes with breathing exercises measured by continuous Holter monitoring
Timepoint [1] 307656 0
During 3-minute intervention
Secondary outcome [1] 352503 0
QT interval change during usual activity measured by continuous Holter monitoring
Timepoint [1] 352503 0
The 24 hour period after the intervention
Secondary outcome [2] 352505 0
Heart rate variability during usual activities measured by continuous Holter monitoring
Timepoint [2] 352505 0
The 24 hour period after the intervention

Eligibility
Key inclusion criteria
Twenty four women with a past history of admission to hospital with either takotsubo syndrome or a non –ST elevation acute coronary syndrome (NSTEACS). There will be twelve in each group.

Takotsubo syndrome will be defined according to modified-Mayo criteria. That is a hospital presentation with a troponin elevation, a recognised regional wall motion pattern that fully resolves and absence of culprit coronary artery disease on coronary angiography.

Non-ST elevation acute coronary syndrome is defined as a hospital presentation with either unstable angina or non-ST elevation myocardial infarction.
Minimum age
18 Years
Maximum age
No limit
Sex
Females
Can healthy volunteers participate?
No
Key exclusion criteria
Impaired left ventricular function (LVEF <50%)
Current therapy with beta blockade
History of panic disorder
Atrial fibrillation
Left bundle branch block

Study design
Purpose of the study
Diagnosis
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Randomisation by online random number generator, This will be concealed from the person recruiting subjects who will have to approach the principal investigator for randomisation after each recruitment.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Permuted block randomisation
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s

The people assessing the outcomes
Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
12/11/2018
Actual
12/11/2018
Date of last participant enrolment
Anticipated
31/03/2019
Actual
9/02/2019
Date of last data collection
Anticipated
31/05/2019
Actual
18/02/2019
Sample size
Target
24
Accrual to date
Final
24
Recruitment outside Australia
Country [1] 20893 0
New Zealand
State/province [1] 20893 0
Canterbury

Funding & Sponsors
Funding source category [1] 300754 0
Charities/Societies/Foundations
Name [1] 300754 0
Heart Foundation of New Zealand
Country [1] 300754 0
New Zealand
Primary sponsor type
Individual
Name
Dr Paul Bridgman
Address
Cardiology Department
Christchurch Hospital
Riccarton Avenue
Christchurch Central
Christchurch 8011
Country
New Zealand
Secondary sponsor category [1] 300290 0
Individual
Name [1] 300290 0
Dr Cameron Lacey
Address [1] 300290 0
Christchurch Hospital
Riccarton Avenue
Christchurch Central
Christchurch 8011
Country [1] 300290 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 301531 0
Southern Health and Disability Ethics Committee
Ethics committee address [1] 301531 0
Ethics committee country [1] 301531 0
New Zealand
Date submitted for ethics approval [1] 301531 0
04/07/2018
Approval date [1] 301531 0
03/09/2018
Ethics approval number [1] 301531 0
18/STH/159

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 87310 0
Dr Paul Bridgman
Address 87310 0
Cardiology Department
Christchurch Hospital
Riccarton Ave
Christchurch Central
Christchurch 8011
Country 87310 0
New Zealand
Phone 87310 0
+64 33640640
Fax 87310 0
Email 87310 0
Paul.Bridgman@cdhb.health.nz
Contact person for public queries
Name 87311 0
Paul Bridgman
Address 87311 0
Cardiology Department
Christchurch Hospital
Riccarton Ave
Christchurch Central
Christchurch 8011
Country 87311 0
New Zealand
Phone 87311 0
+64 33640640
Fax 87311 0
Email 87311 0
Paul.Bridgman@cdhb.health.nz
Contact person for scientific queries
Name 87312 0
Paul Bridgman
Address 87312 0
Cardiology Department
Christchurch Hospital
Riccarton Ave
Christchurch Central
Christchurch 8011
Country 87312 0
New Zealand
Phone 87312 0
+64 33640640
Fax 87312 0
Email 87312 0
Paul.Bridgman@cdhb.health.nz

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
All relevant summary data will be provided in a paper submitted for publication. The Canterbury District Health Board does not grant permission for the raw data to be made publicly available due to ethical and legal restrictions.


What supporting documents are/will be available?

Doc. No.TypeCitationLinkEmailOther DetailsAttachment
5551Ethical approval  Paul.Bridgman@cdhb.health.nz 376063-(Uploaded-26-10-2019-12-20-27)-Study-related document.pdf
5552Informed consent form  Paul.Bridgman@cdhb.health.nz



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
SourceTitleYear of PublicationDOI
EmbaseA randomised cross-over trial of QT response to hyperventilation-induced anxiety and diaphragmatic breathing in patients with stress cardiomyopathy and in control patients.2022https://dx.doi.org/10.1371/journal.pone.0265607
N.B. These documents automatically identified may not have been verified by the study sponsor.