Publications by authors named "Kris J Norris"
Objectives: This study sought to determine whether variations in NOS1AP affect drug-induced long QT syndrome (LQTS).
Background: Use of antiarrhythmic drugs is limited by the high incidence of serious adverse events including QT prolongation and torsades de pointes. NOS1AP gene variants play a role in modulating QT intervals in healthy subjects and severity of presentation in LQTS.
Background: The degree of QT prolongation by drug is highly variable and related to risk for polymorphic ventricular tachycardia due to drugs.
Objective: The purpose of this study was to determine factors that affect the degree of QT prolongation by drugs.
Methods: QT and QTc were measured before and after administration of the QT-prolonging drug ibutilide in 253 normal volunteers aged 18 to 40 years.
Introduction: QT interval for a given heart rate differs between exercise and recovery (QT hysteresis) due to slow QT adaptation to changes in heart rate. We hypothesized that QT hysteresis is evident within stages of exercise and investigated which component of the QT contributes to hysteresis.
Methods And Results: Nineteen healthy volunteers performed a staged exercise test (four stages, 3 min each).
Introduction: The QT interval is a predictor of sudden death. Many drugs prolong the QT, primarily through I(Kr) block. Autonomic tone directly affects heart rate and ventricular repolarization, but its effects in the setting of I(Kr) block are unknown.
View Article and Find Full Text PDFObjectives: The purpose of this study was to test for a genetic component to risk for acquired long QT syndrome (LQTS).
Background: Many drugs prolong the QT interval, and some patients develop excessive QT prolongation and occasionally torsades de pointes-the acquired LQTS. Similarities between the acquired and congenital forms of the long QT syndrome suggest genetic factors modulate susceptibility.