Measurement of the Electromechanical Window to Improve the Diagnosis of Congenital Long QT Syndrome

Long QT Syndrome Clinical Trial

— FEMQT  

Official title:

Measurement of the Electromechanical Window to Improve the Diagnosis of Congenital Long QT Syndrome

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04328376
• Other study ID #: CHUBX 2019/35
• Status: Completed
• Phase: N/A
• Start date: August 28, 2020
• Est. completion date: April 23, 2024

Study information

• Verified date: June 2024
• Source: University Hospital, Bordeaux
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 224
• Est. completion date: April 23, 2024
• Est. primary completion date: April 23, 2024
• Accepts healthy volunteers: No
• Gender: All
• Age group: 12 Years and older

Eligibility

Inclusion Criteria:

• 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.

Exclusion Criteria:

• 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.

Related Conditions & MeSH terms

• Long QT Syndrome
• Syndrome

Intervention

Diagnostic Test:
• ECG coupled to phonocardiography
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.

Locations

Country	Name	City	State
France	Nantes University Hospital	Nantes
France	Bordeaux University Hospital	Pessac
France	La Réunion University Hospital	Saint-Pierre
France	Toulouse University Hospital	Toulouse

Sponsors (1)

Lead Sponsor	Collaborator
University Hospital, Bordeaux

Country where clinical trial is conducted

France, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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.	Day 1
Secondary	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.	Day 1
Secondary	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.	Day 1
Secondary	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.	Day 1
Secondary	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.	Day 1