Electromechanical Profiling of the Long-QT Syndrome (LQTS)

• Conditions: Long QT Syndrome; Ventricular Tachycardia; Sudden Cardiac Death
• Interventions: Diagnostic Test: Adenosine and epinephrine, isoprenaline provocation

• Registration Number: NCT04074122
• Lead Sponsor: Maastricht University Medical Center

Brief Summary

High-resolution, non-invasive electromechanical mapping in genotyped long-QT syndrome patients and healthy controls at baseline and during smart provocation.

Detailed Description

Using simultaneous ECG-imaging, speckle-tracking analysis and tissue-phase mapping with MRI we will assess electromechanical dispersion at rest. Regional electromechanical elasticity will be investigated during adenosine and epinephrine, isoprenaline infusions and is postulated to increase sudden cardiac death risk prediction in the individual patient.

Study Timeline

• Study First Submitted: 2019-07-05
• Status Verified: 2019-08
• Study First Submitted QC: 2019-08-28
• Last Update Submitted: 2019-08-28
• Study First Posted: 2019-08-29
• Last Update Posted: 2019-08-29
• Study Start: 2020-01-01
• Primary Completion: 2022-01-01
• Study Completion: 2022-01-01

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 150

Inclusion Criteria

LQTS group (Group 1):

• Diagnosis of LQTS according to the ESC guidelines.
• Genetic testing either already performed or consent to genetic testing (at least 5 major LQTS-related genes tested: KCNQ1, KCNH2, SCN5A, KCNE1, KCNE2).

Control group (Group 2):

> Control subjects with structurally normal hearts.

Exclusion Criteria

• Pregnancy, nursing or planning to become pregnant.
• Known allergy or strong reaction to skin electrodes or contrast agent.
• Inability to give informed consent.
• Presence of metal objects in or attached to the body.
• Dialysis.
• Cardiomyopathy.
• Second-degree heart block or higher degrees of block.
• Sick sinus syndrome.
• Asthma.
• Chronic obstructive pulmonary disease.
• Left-main coronary artery disease.
• Unstable coronary artery disease.

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Asymptomatic LQTS patients	Adenosine and epinephrine, isoprenaline provocation	Pharmacological (adenosine, epinephrine, isoprenaline) provocation, ECG-imaging and tissue-phase mapping using magnetic resonance imaging (TPM-MRI).
Healthy controls	Adenosine and epinephrine, isoprenaline provocation	Pharmacological (adenosine, epinephrine, isoprenaline) provocation, ECG-imaging and tissue-phase mapping using magnetic resonance imaging (TPM-MRI).
Symptomatic LQTS patients	Adenosine and epinephrine, isoprenaline provocation	Pharmacological (adenosine, epinephrine, isoprenaline) provocation, ECG-imaging and tissue-phase mapping using magnetic resonance imaging (TPM-MRI).

Primary Outcome Measures

Name	Time	Method
Differences in regional electromechanical dispersion between LQTS patients and controls	At day of investigation	Electromechanical dispersion in milliseconds
Differences in regional electromechanical dispersion between symptomatic and asymptomatic LQTS patients	At day of investigation	Electromechanical dispersion in milliseconds

Secondary Outcome Measures

Name	Time	Method
Relation between global electromechanical window vs regional electromechanical dispersion in LQTS	At day of investigation	Electromechanical dispersion in milliseconds
Correlation of electromechanical dispersion between LQTS type 1, 2, and 3.	At day of investigation	Electromechanical dispersion in milliseconds
Correlation between mechanical dispersion using TPM-MRI and cine-MRI	At day of investigation	Time-to-diastolic peak in milliseconds
Correlation between mechanical dispersion using TPM-MRI and speckle-tracking echocardiography	At day of investigation	Time-to-peak in milliseconds