ISSN:
1542-474X
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
This study was designed to evaluate several alternative ECG measurements and provocative tests in order to identify markers for children with suspect congenital long QT syndrome (LQTS).〈section xml:id="abs1-2"〉〈title type="main"〉BackgroundA single QTc measurement on a resting ECG does not identify all children with LQTS. Alternative ECG measurements have been established for identification of LQTS patients, with varied degrees of accuracy. Additionally, findings of QT prolongation during exercise or catecholaminergic stimulation have been suggested as indicators for the presence of LQTS and associated arrhythmias.〈section xml:id="abs1-3"〉〈title type="main"〉MethodsThe ECGs from 40 children with suspect congenital LQTS were compared with 1000 gender and age matched control patients. Complete exercise ECG studies were performed on 32 of the 40 suspect LQTS patients and compared with 29 controls. ECGs recorded during isoproterenol infusion were obtained in 9 suspect LQTS patients and compared with 44 matched control subjects.〈section xml:id="abs1-4"〉〈title type="main"〉ResultsDuring exercise, the QTc was mildly prolonged in both groups, without a similar increase in JTc, suggesting prolongation of depolarization time. QT and JT dispersion shortened with exercise in control subjects, but not in the suspect LQTS patients. During isoproterenol infusion, the QTc and JTc are prolonged in the suspect LQTS group, without an increase in the control patients.〈section xml:id="abs1-5"〉〈title type="main"〉ConclusionsWe describe the ECG findings with provocative testing in patients in whom there is a clinical suspicion of LQTS, yet have a normal or borderline QTc. Exercise or isoproterenol may aid in identification of patients with congenital long QT syndrome.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1542-474X.1998.tb00023.x
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