Prognostic Significance of Quantitative QRS Duration

Background Although QRS duration is known to be a predictor of mortality in patients with left ventricular dysfunction, our purpose was to evaluate the prognostic power of computer-measured QRS duration in a general medical population. Methods Analyses were performed on the first electrocardiogram digitally recorded on 46,933 consecutive patients at the Palo Alto Veterans Affairs Medical Center between 1987 and 2000. Patients with electrocardiograms exhibiting Wolff-Parkinson-White were excluded (n = 44), and those with bundle branch block or electronic pacing were considered separately, leaving 44,280 patients for analysis (mean age 56 ± 15 years; 90% were males). There were 3659 (8.3%) cardiovascular deaths (mean follow-up of 6.0 ± 3.8 years). Results A survival plot showed significant separation according to a QRS duration score. After adjustment in the Cox model for age, gender, and heart rate, the QRS duration score was a strong independent predictor of cardiovascular mortality. For every 10-ms increase in QRS duration, there was an 18% increase in cardiovascular risk. The results were similar in patients with an abnormal electrocardiogram, a bundle branch block, and a paced rhythm. Conclusion Quantitative QRS duration was a significant and independent predictor of cardiovascular mortality in a general medical population.