Usefulness of spatial dispersion of QRS duration in predicting mortality in patients with mild to moderate chronic heart failure.

To prospectively evaluate the prognostic significance of spatial dispersion of QRS duration (S-QRSd) on a signal-averaged electrocardiogram in patients with chronic heart failure (CHF), we studied 114 consecutive stable outpatients with radionuclide left ventricular ejection fraction <40%. Cardiac and sudden deaths were significantly more often observed in patients with than without abnormal S-QRSd. S-QRSd is a powerful prognostic marker of the mortality in patients with mild to moderate CHF.