OBJECTIVE To investigate whether QT dispersion is a reliable index of the severity of aortic stenosis and left ventricular hypertrophy in the setting of aortic stenosis.

DESIGN A retrospective analysis of the results of echocardiography and electrocardiography before and after aortic valve replacement.

SETTING Tertiary centre.

PATIENTS 36 men (30 white and six black) with symptomatic aortic stenosis requiring valve replacement.

RESULTS All patients had significant aortic stenosis (mean (SD) aortic valve area 0.68 (0.18) cm²) and evidence of left ventricular hypertrophy (left ventricular mass index (LVMI): 267 (90) g/m²). Before aortic valve replacement, QT dispersion was correlated with mean aortic valve area and LVMI (r = 0.697, p < 0.001, and r = 0.59, p < 2.4 × 10⁻⁶, respectively). QT dispersion and QT corrected for heart rate dispersion decreased from 133 (54) to 71 (33) ms and from 151 (64) to 94 (76) ms, respectively (p < 0.001 for both). LVMI regressed after aortic valve replacement to 190 (79) g/m², p < 0.01.

CONCLUSIONS QT dispersion is increased in association with LVMI in patients with significant symptomatic aortic stenosis. Aortic valve replacement reduces QT dispersion and LVMI. QT dispersion could be a useful indicator of risk and risk reduction in patients with significant symptomatic aortic stenosis.