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Microvolt T-wave alternans in short QT syndrome
Philippe Maury1, Fabrice Extramiana, Carla Giustetto
1University Hospital Rangueil, Toulouse, France University Hospital Bichat Paris, France. mauryjphil@hotmail.com
Pacing and Clinical Electrophysiology : PACE
|August 18, 2012
Summary
T-wave alternans (TWA) testing is largely negative in Short QT Syndrome (SQTS) patients, suggesting it is not a useful risk stratification tool for this rare electrical disorder.
Area of Science:
- Cardiology
- Electrophysiology
- Genetics
Background:
- T-wave alternans (TWA) is a recognized marker for malignant ventricular arrhythmias.
- Short QT Syndrome (SQTS) is a rare genetic disorder associated with ventricular fibrillation risk.
- The prognostic value of TWA in SQTS has not been previously investigated.
Purpose of the Study:
- To evaluate the utility of microvolt T-wave alternans (TWA) measurement for risk stratification in patients with Short QT Syndrome (SQTS).
Main Methods:
- Thirteen patients diagnosed with SQTS underwent microvolt T-wave alternans (TWA) testing using spectral analysis during bicycle exercise.
- TWA results were classified as negative, positive, or indeterminate based on established clinical interpretation standards.
Main Results:
- TWA was negative in 12 out of 13 SQTS patients; one result was indeterminate.
- The study included male patients with varying symptoms, including aborted sudden cardiac death and syncope.
- Some patients had a family history of SQTS or sudden death, and ventricular fibrillation was inducible in three patients.
Conclusions:
- Microvolt T-wave alternans (TWA) testing appears to be negative in most Short QT Syndrome (SQTS) patients, including those with symptoms or inducible arrhythmias.
- Conventional TWA protocols and criteria may not be useful for risk stratification in SQTS.
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