QT dispersion in nonsustained ventricular tachycardia and coronary artery disease.

This study examines the relation between QT dispersion and the inducibility of ventricular tachycardia (VT) in 35 consecutive patients with coronary artery disease who underwent electrophysiologic testing for evaluation of nonsustained VT. The mean age of the patients was 66 +/- 9 years (+/- SD) and the mean left ventricular ejection fraction was 0.36 +/- 0.14. In 6 patients in whom sustained, monomorphic VT was inducible by programmed ventricular stimulation, QT dispersion was significantly greater than in the 29 patients in whom VT was not inducible (126 +/- 35 vs 67 +/- 25 ms, p < 0.001). All patients who had a QT dispersion > 120 ms had inducible sustained monomorphic VT, and no patient who had a QT dispersion < 90 ms had inducible VT. The patients who had inducible VT dis not differ significantly from those who did not with regard to age, gender, ejection fraction, RR interval, or mean QT. In conclusion, in patients with coronary artery disease who have nonsustained VT, inducibility of monomorphic VT is associated with an increase in QT dispersion. QT dispersion may be helpful in predicting which patients with nonsustained VT are and are not likely to have inducible VT by programmed stimulation.