Non-sustained microvolt level T-wave alternans in congenital long QT syndrome types 1 and 2

作者：Kannampuzha Jovil A; Sengodan Prasanna; Avula Sravani; White Bartholomew; Ganocy Stephen J; Leo Peter J; Kaufman Elizabeth S^*

来源：Journal of Electrocardiology, 2018, 51(2): 303-308.

DOI：10.1016/j.jelectrocard.2017.11.008

• Microvolt T-wave altemans
• Congenital long QT syndrome
• Dispersion of repolarization
• Sudden cardiac death

Background: Patients with long QT syndrome (LQTS) are predisposed to polymorphic ventricular tachycardia (VT) during adrenergic stimulation. Microvolt T-wave altemans (MTWA) is linked to vulnerability to VT in structural heart disease. The prevalence of non-sustained MTWA (NS-MTWA) in LQTS is unknown.
Methods: 31 LQT1, 42 LQT2, and 80 controls underwent MTWA testing during exercise. MTWA tests were classified per standardized criteria, and re-analyzed according to the modified criteria to account for NS-MTWA.
Results: LQT1 and LQT2 patients had a significantly higher frequency of late NS-MTWA (26% and 12%) compared to controls (0%). There was no significant difference between the groups with respect to sustained and early NSMTWA. Late NS-MTWA was significantly associated with QTc.
Conclusion: LQT1 and LQT2 patients had a higher prevalence of late NS-MTWA during exercise than matched controls. NS-MTWA likely reflects transient adrenergically mediated dispersion of repolarization, and could be a marker of arrhythmic risk in LQTS.

• 出版日期2018-4