Short-term reproducibility of T wave alternans measurement.

Introduction: Microvolt T wave alternans (TWA) has been proposed as a strong independent predictor of malignant ventricular tachyarrhythmias and sudden cardiac death. TWA reproducibility during bicycle stress test has not been previously investigated. We sought to assess the short-term reproducibility of TWA, as well as heart rate (HR) threshold for TWA, and its spatial distribution and magnitude.

Efavirenz-associated QT prolongation and Torsade de Pointes arrhythmia.

Objective: To report a case of acquired long QT syndrome that, after exclusion of all other possible causes, was probably related to therapy with efavirenz, a novel nonnucleoside reverse transcriptase inhibitor.

Case Summary: This patient presented with recurrent syncope and polymorphic ventricular tachycardia, which was treated with overdrive ventricular pacing and was eliminated by discontinuation of the offending drug.

Discussion: This is the first reported case of QT prolongation and severe ventricular arrhythmia associated with the use of efavirenz.