Exploring Mechanisms and Morphology of QT Interval Prolongation

Study Overview
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Brief Summary
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The projects will try and optimise the risk stratification for patients with Long QT syndrome by investigating how the exposure of physical and acoustic stress will affect the QT-dynamics and if beta blockers protect against arrhythmias by suppressing this dynamic QT-prolongation. Furthermore, the project will investigate the effects of Spironolactone on the QT-dynamics tested by Brisk Standing. First, patients are tested with known arrhythmic triggers and they are then administered thier normal dose of beta blockers. Hereafter, Brisk Standing test is performed and the patients are on Spironolactone for seven days. After seven days treatment the Brisk Standing is repeated.

Detailed Description
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The aim of the projects is to try and optimise the risk stratification for patients with Long QT syndrome by investigating how the exposure of physical and acoustic stress will affect the QT-dynamics and if beta blockers protect against arrhythmias by suppressing this dynamic QT-prolongation. Furthermore, the project will investigate the effects of Spironolactone on the QT-dynamics tested by Brisk Standing. First, patients are tested with known arrhythmic triggers and they are then administered thier normal dose of beta blockers. Hereafter, Brisk Standing test is performed and the patients are on Spironolactone for seven days. After seven days treatment the Brisk Standing is repeated.

Official Title
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Exploring Mechanisms and Morphology of QT Interval Prolongation - An Inheritable as Well as an Inducible Phenomenon

Conditions
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Long Qt Syndrome 1-2, Sudden Cardiac Death

Intervention / Treatment
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* Drug: Beta Blockers
* Drug: Spironolactone


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Verified Long QT syndrome mutation, subtype 1 or 2. over 18 years of age Exclusion Criteria: Atrioventricular block, Left bundle branch block, Left ventricular hypertrophy, Pace rhythm, ST-deviations >1 mm), Left ventricular ejection fraction <50 % and significant valvulopathy, Unstable psychiatric disease Unstable cardiovascular disease.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Beta Blockers<br>With and without Beta Blockers | Drug: Beta Blockers<br>* With and without Beta Blockers<br>|
| Experimental: Spironolactone<br>With and without Spironolactone | Drug: Spironolactone<br>* Brisk Standing before and after seven days treatment with Spironolactone<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| QTc | Corrected QT | 7 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Long QT Syndrome