The prognostic value of QT dispersion in patients with acute neurological events without known cardiac disease

Abstract

BackgroundElectrocardiographic changes are known to occur in patients with acute neurological events but their significance remains uncertain. QT dispersion (QTD) reflects heterogeneity of myocardial repolarization, which is modulated by the central nervous system. QTD has been shown to predict adverse outcomes in various cardiac states. ObjectiveTo determine the degree of QTD and its relation to outcome in patients with acute neurological events. MethodsWe studied 40 patients admitted to our hospital with acute neurological events and without known cardiac disease. Simultaneous 12-lead ECG was done within 24h of the onset. QTD was calculated manually as the difference between maximum and minimum QT intervals in at least 11 of 12 leads. Modified Rankin Scale (MRS) was used to assess functional status after 3months from the onset. ResultsIncreased QTD in the 24h-ECG following the onset of acute neurological events (median=60, range, 20–120ms). QTD was higher in patients with intercerebral hemorrhage as compared to non hemorrhagic stroke (67±16 versus 52±26ms; p=0.04). The increase in QTD was associated with lower functional outcomes on Modified Rankin Scale ((r=0.65 and p=0.001) and with a higher mortality (p=0.006) at 3months follow-up. On multivariate analysis, the most independent predictors of mortality were QTD (odds ratio, 1.13; 95% confidence interval, 1.03–1.25) and GCS (odds ratio, 0.366; 95% confidence interval, 0.177–0.758). ConclusionProlonged QTD in the first 24h of acute neurological events is an independent predictor of short-term functional outcome and mortality following.