Exploring Mechanisms and Morphology of QT Interval Prolongation

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

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.

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.

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.