Long QT SyndromeFEMQTNCT04328376
Measurement of the Electromechanical Window to Improve the Diagnosis of Congenital Long QT Syndrome
A study testing ECG coupled to phonocardiography in people with Long QT Syndrome, run by University Hospital, Bordeaux at 4 sites in France.
Trial summary
The goal of this research is to prospectively evaluate the performance of the electromechanical window according to a phonographic method, as a mean of diagnosis of long QT syndrome, and to compare its performance with routine tests used. Read more about this study
- Who is it for?
- Ages 12 years and older
- Conditions the study is for
- Long QT Syndrome
- What is being tested?
- ECG coupled to phonocardiography
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 224 participants
- Where
- 4 sitesFrance
- Study dates
- 28 Aug 2020to 23 Apr 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 12 years and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Propositus patients with genetically proven LQTS and their relatives,
- Patients of both sexes aged 12 and over,
- Free, informed and written consent of the patient and the two holders of parental authority for minors.
Who cannot join
- Inability to consent,
- Person deprived of liberty by judicial or administrative decision,
- Majors subject to a legal protection measure,
- Person participating in another research including an exclusion period still in progress,
- Severely impaired physical and / or psychological health, which, according to the investigator, may affect the participant's compliance with the study.
Trial locations and contacts
4 sites in 1 country.
France4 sites
Nantes University Hospital
Nantes, 44093
Bordeaux University Hospital
Pessac, 33604
La Réunion University Hospital
Saint-Pierre, 97410
Toulouse University Hospital
Toulouse, 31400
About this study
The goal of this research is to prospectively evaluate the performance of the electromechanical window according to a phonographic method, as a mean of diagnosis of long QT syndrome, and to compare its performance with routine tests used.
Read the detailed description
Familial long QT syndrome (LQTS) is a hereditary cardiac disorder in which most affected family members have delayed ventricular repolarization manifest on the electrocardiogram (ECG) as QT prolongation. This disease is associated with an increased propensity to palpitations, syncope, polymorphous ventricular tachycardia and sudden arrhythmic death. The diagnosis relies mostly on resting ECG findings and on genetic testing. In clinical practice however, this diagnosis is complicated by 2 main reasons: 1) a significant overlap in ECG findings between healthy and diseased individuals and 2) a frequent identification of genetic variants of unknown significance. Recent studies have suggested that echocardiographic measurement of the electromechanical window (EMW - the delay between the end of mechanical contraction and electrical activation of the heart) has better performance in the diagnosis of LQTS. The echocardiographic technique is however too complicated for routine clinical use. Preliminary work conducted at the University Hospital of Bordeaux and at the University Hospital of Reunion Island has demonstrated that a phonocardiographic approach leads to similar results with an improved feasibility and a good reproducibility.
- Conditions
- Long QT Syndrome
- Being tested
- ECG coupled to phonocardiography
- Keywords
- Long QT syndrome, Electromechanical window, Phonocardiography
- Medical subject headings
- Long QT Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ECG coupled to phonocardiographyDiagnostic test
A standard ECG is recorded along with a phonocardiographic recording. The phonocardiographic recording is obtained by using a specific electronic stethoscope plugged into the auxiliary port of the ECG machine. The recording takes less than 30 seconds. The two recording methods are concomitant.
QT interval is measured on the ECG recording, EMW is measured with ECG coupled to phonocardiography.
| Study group | Role | What they receive |
|---|---|---|
| Prospective FEMQT Group | Experimental | Propositus patients with genetically proven LQTS and their relatives Receives: Diagnostic Test: ECG coupled to phonocardiography |
What is being measured
The primary outcome is the main question the study is designed to answer.
Negative predictive value (NPV) obtained by the two methods of diagnosis
The NPV is measured in percentage. The NPV of LQTS diagnosis obtained by phonocardiographic method (measurement of the EMW) and the NPV obtained by standard ECG method (QT measurement prolongation) will be compared.
Measured: Day 1
Secondary outcomes (4)
Values of sensitivity obtained by the two methods of diagnosis
Value of sensitivity is measured in percentage. The values of sensitivity of EMW and standard ECG will be compared.
Measured: Day 1
Values of specificity obtained by the two methods of diagnosis
Value of specificity is measured in percentage. The values of specificity of EMW and standard ECG will be compared.
Measured: Day 1
Positive predictive values obtained by the two methods of diagnosis
Positive predictive value is measured in percentage. Positive predictive values of EMW and standard ECG will be compared.
Measured: Day 1
Area Under the Curves (AUC) obtained by the two methods of diagnosis
The AUC obtained by Receiver Operating Characteristic (ROC) analyses is measured by a value between 0 and 1.
The AUC obtained by ROC of EMW and standard ECG will be compared.
Measured: Day 1
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 Mar 2020
- Study start28 Aug 2020
- Primary completion23 Apr 2024
- Study completion23 Apr 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Long QT SyndromeStudies of the same condition, open and under way.
- More trials run by University Hospital, BordeauxThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 224 participants (actual)
Sponsor and investigators
- Lead sponsor
- University Hospital, Bordeaux
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Josselin DUCHATEAU, MD, Principal investigator, University Hospital, Bordeaux
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04328376
- Sponsor's protocol ID
- CHUBX 2019/35
- Acronym
- FEMQT
- Status last verified
- Jun 2025
- First submitted
- 27 Mar 2020
- Last updated
- 17 Jun 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 17 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Measurement of the Electromechanical Window to Improve the Diagnosis of Congenital Long QT Syndrome
- ClinicalTrials.gov ID
- NCT04328376
- Acronym / sponsor ID
- FEMQT / CHUBX 2019/35
- Conditions
- Long QT Syndrome
- Keywords
- Long QT syndrome, Electromechanical window, Phonocardiography
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 224 participants (actual)
- Lead sponsor
- University Hospital, BordeauxUniversity, hospital or other
- Study start
- 28 Aug 2020 (actual)
- Primary completion
- 23 Apr 2024 (actual)
- Study completion
- 23 Apr 2024 (actual)
- First posted
- 31 Mar 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this research is to prospectively evaluate the performance of the electromechanical window according to a phonographic method, as a mean of diagnosis of long QT syndrome, and to compare its performance with routine tests used.
Detailed description
Familial long QT syndrome (LQTS) is a hereditary cardiac disorder in which most affected family members have delayed ventricular repolarization manifest on the electrocardiogram (ECG) as QT prolongation. This disease is associated with an increased propensity to palpitations, syncope, polymorphous ventricular tachycardia and sudden arrhythmic death. The diagnosis relies mostly on resting ECG findings and on genetic testing. In clinical practice however, this diagnosis is complicated by 2 main reasons: 1) a significant overlap in ECG findings between healthy and diseased individuals and 2) a frequent identification of genetic variants of unknown significance. Recent studies have suggested that echocardiographic measurement of the electromechanical window (EMW - the delay between the end of mechanical contraction and electrical activation of the heart) has better performance in the diagnosis of LQTS. The echocardiographic technique is however too complicated for routine clinical use. Preliminary work conducted at the University Hospital of Bordeaux and at the University Hospital of Reunion Island has demonstrated that a phonocardiographic approach leads to similar results with an improved feasibility and a good reproducibility.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Prospective FEMQT Group | Experimental | Diagnostic Test: ECG coupled to phonocardiographyPropositus patients with genetically proven LQTS and their relatives |
Who may qualify
- Ages
- 12 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (3 listed)
- Propositus patients with genetically proven LQTS and their relatives,
- Patients of both sexes aged 12 and over,
- Free, informed and written consent of the patient and the two holders of parental authority for minors.
Key exclusion criteria (5 listed)
- Inability to consent,
- Person deprived of liberty by judicial or administrative decision,
- Majors subject to a legal protection measure,
- Person participating in another research including an exclusion period still in progress,
- Severely impaired physical and / or psychological health, which, according to the investigator, may affect the participant's compliance with the study.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ECG coupled to phonocardiographyA standard ECG is recorded along with a phonocardiographic recording. The phonocardiographic recording is obtained by using a specific electronic stethoscope plugged into the auxiliary port of the ECG machine. The recording takes less than 30 seconds. The two recording methods are concomitant. QT interval is measured on the ECG recording, EMW is measured with ECG coupled to phonocardiography. | Diagnostic test | Prospective FEMQT Group |
Primary outcome
Negative predictive value (NPV) obtained by the two methods of diagnosis
Time frame: Day 1
The NPV is measured in percentage. The NPV of LQTS diagnosis obtained by phonocardiographic method (measurement of the EMW) and the NPV obtained by standard ECG method (QT measurement prolongation) will be compared.
4 secondary outcomes
Values of sensitivity obtained by the two methods of diagnosis
Time frame: Day 1
Values of specificity obtained by the two methods of diagnosis
Time frame: Day 1
Positive predictive values obtained by the two methods of diagnosis
Time frame: Day 1
Area Under the Curves (AUC) obtained by the two methods of diagnosis
Time frame: Day 1
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Jun 2025.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Josselin DUCHATEAU, MD principal investigator
University Hospital, Bordeaux
4 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing ECG coupled to phonocardiography in people with Long QT Syndrome, run by University Hospital, Bordeaux at 4 sites in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 17 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 4 sites in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Negative predictive value (NPV) obtained by the two methods of diagnosis (time frame: Day 1). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Jun 2025.