Journal Article

Comparison of QT dispersion during atrial fibrillation and sinus rhythm in the same patients, at normal and prolonged ventricular repolarization

B. Houltz, B. Darpö, K. Swedberg, P. Blomström, H.J.G.M. Crijns, S.M. Jensen, E. Svernhage and N. Edvardsson

in EP Europace

Published on behalf of European Heart Rhythm Association of the European Society of Cardiology (ESC)

Volume 2, issue 1, pages 20-31
Published in print January 2000 | ISSN: 1099-5129
Published online January 2000 | e-ISSN: 1532-2092 | DOI: http://dx.doi.org/10.1053/eupc.1999.0068
Comparison of QT dispersion during atrial fibrillation and sinus rhythm in the same patients, at normal and prolonged ventricular repolarization

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Aims

Drug-induced increase in QT dispersion has been associated with increased risk of ventricular proarrhythmia. The aim of the present study was to compare QT dispersion during atrial fibrillation and sinus rhythm in the same patients at normal and prolonged ventricular repolarization.

Methods and Results

Sixty-one patients who had had chronic atrial fibrillation for 8±14 months received a 6 h infusion of the Ikr-blocker almokalant, the first 90 min of which are used for this analysis. The following day, after conversion to sinus rhythm, by almokalant (n=19) or direct current cardioversion (n=42), an identical 90 min infusion was administered. Prior to infusion, there was no difference in precordial QT dispersion between atrial fibrillation and sinus rhythm (29±12 vs 36±17 ms, P=ns). During infusion, at prolonged repolarization, the increase in QT dispersion was greater during sinus rhythm than during atrial fibrillation (58±49 vs 30±15 ms,P =0·0011, after 30 min infusion). No correlation was found between QT dispersion and the QT or RR interval.

Conclusion

QT dispersion during atrial fibrillation does not differ from QT dispersion during sinus rhythm during normal repolarization, while measurement of QT dispersion during prolonged repolarization, induced by an Ikr-blocker, yielded larger values during sinus rhythm than during atrial fibrillation.

Keywords: QT dispersion; ventricular repolarization; class III antiarrhythmic agent; atrial fibrillation; sinus rhythm; almokalant

Journal Article.  0 words. 

Subjects: Cardiovascular Medicine

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