LQT and Smartphone/Smartwatch

Study Overview
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Brief Summary
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Congenital long QT syndrome (LQTS) is a rare genetic disorder characterized by prolongation of the corrected QT interval (QTc) on the electrocardiogram. LQTS is associated with a risk of syncope or sudden death from ventricular arrhythmia. The increase in the duration of the corrected QT interval and / or changes in the morphology of the T wave on the electrocardiogram are markers of an increased risk of sudden death and syncope. Recently, a personal portable 6-lead device (DI, DII, DIII, aVF, aVL and aVR) connected to the patient's smartphone has entered the market (KARDIA MOBILE 6L, AliveCor, Mountain View, CALIFORNIA, USA). The APPLE WATCH Series 6 (Apple, Cupertino, CA, USA) can also record an ECG. If the device is designed to record a single lead (DI), several works have shown that it is possible to record 9 leads (DI, DII, DIII, V1, V2, V3, V4, V5 and V6) by moving simply the device (Spaccarotella CAS et al. JAMA Cardiology 2020). These devices were originally designed to screen for atrial fibrillation, but they produce accurate 6- and 9-lead ECGs and could potentially allow ambulatory ECG monitoring of patients with LQTS.

Official Title
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Smartphone and Smartwatch Based ECG for Patients With Congenital Long QT Syndrome

Conditions
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Long QT Syndrome

Intervention / Treatment
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* Other: LQT


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient with diagnosis of LQTS based on the following criteria: Corrected QT (Qtc) interval according to Bazett method ≥ 480 ms, at several times in the absence of a secondary cause and / or class 4 or 5 mutation in a gene involved in long QT syndrome and / or syncope (s) and QTc> 460ms in the absence of other cause All ages No opposition from the patient Exclusion Criteria: None -
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

| Intervention/Treatment |
| --- |
|Other: LQT|Patients with LQT syndrome diagnosis.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| the duration of the QTc (ms) | The primary outcome is the measurement of 3 data: - the duration of the QTc (ms). These data will be measured during the same inclusion visit with 1/ the standard 12-lead ECG machine, 2/ the KARDIA MOBILE 6L and 3/the APPLE WATCH Series 6. The data of the Kardia Mobile 6L and the Apple Watch series 6 will be compared to the data of the gold standard a 12-lead ECG. | at the inclusion visit | 
| the morphology of the T waves (bpm). | - the morphology of the T waves (bpm). These data will be measured during the same inclusion visit with 1/ the standard 12-lead ECG machine, 2/ the KARDIA MOBILE 6L and 3/the APPLE WATCH Series 6. The data of the Kardia Mobile 6L and the Apple Watch series 6 will be compared to the data of the gold standard a 12-lead ECG. | at the inclusion visit | 
| the heart rate (bpm). | - the heart rate (bpm). These data will be measured during the same inclusion visit with 1/ the standard 12-lead ECG machine, 2/ the KARDIA MOBILE 6L and 3/the APPLE WATCH Series 6. The data of the Kardia Mobile 6L and the Apple Watch series 6 will be compared to the data of the gold standard a 12-lead ECG. | at the inclusion visit |