Acquired Long-QT Syndrome: Mild but Abnormal?

Genetics of acquired long QT syndrome.

The QT interval is the electrocardiographic manifestation of ventricular repolarization, is variable under physiologic conditions, and is measurably prolonged by many drugs. Rarely, however, individuals with normal base-line intervals may display exaggerated QT interval prolongation, and the potentially fatal polymorphic ventricular tachycardia torsade de pointes, with drugs or other environmen...

Is long QT syndrome a disease of abnormal mechanical contraction?

It is generally assumed that long QT syndrome (LQTS) is an arrhythmic disorder that occurs in patients with normal left ventricular systolic function. The present article by Haugaa et al challenges this assumption.1 One hundred and one patients with genetically documented LQTS were systematically compared to an age-matched unaffected control population for differences in regional contraction pa...

Selective acquired long QT syndrome (saLQTS) upon risperidone treatment

BACKGROUND Numerous structurally unrelated drugs, including antipsychotics, can prolong QT interval and trigger the acquired long QT syndrome (aLQTS). All of them are thought to act at the level of KCNH2, a subunit of the potassium channel. Although the QT-prolonging drugs are proscribed in the subjects with aLQTS, the individual response to diverse QT-prolonging drugs may vary substantially. ...

Elderly patient with acquired long QT syndrome secondary to Levetiracetam.

Abnormal QT responses to adenosine in subjects with long-QT syndrome.

In the interesting article by Viskin et al., adenosine-induced bradycardia was found to produce a higher increase in QT and a lower decrease in QTc (calculated using the Bazett formula) in subjects with long-QT syndrome (LQTS) than in controls. However, a major issue in this study concerns the reliability of QT correction when large ranges of heart rates are analysed. The Bazett formula overcor...