Electrocardiographic markers of impaired left ventricular ejection performance in aortic stenosis

Abstract

To determine whether the ECG would be useful in the prediction of impaired left ventricular ejection performance in aortic valve stenosis, the authors evaluated 121 patients according to (1) the time relationship of the R peak in V 6 to the S peak in V 2; and (2) the negative P wave terminal force in V 1 (Morris index, n = 109). Left ventricular ejection fraction (LVEF) was significantly depressed in patients with the R peak in V 6 later than the S peak in V 2 (R peak delay in V 6, n = 24), compared with those with the R peak in V 6 preceding the S peak in V 2 or with both peaks occurring simultaneously (n = 97) (LVEF 40.8 ± 11.8% vs 69.9 ± 13.3%, p = .000). LVEF < 55% was present in 87.5% of patients with the R peak delay in V 6 and in only 23.7% of those without this finding. The Morris Index was significantly greater in patients with LVEF < 55% (n = 39) than in those with LVEF ≥ 55% (n = 70) (Morris Index 0.063 ± 0.035 msec vs 0.030 ± 0.025 msec, p = .000). The R peak delay in V 6 is a highly specific (96.1%), but less sensitive (47.7%), indicator of depressed LVEF, its positive predictive value and predictive accuracy being 87.5% and 78.5%, respectively. Of the Morris indexes, only ≥ 0.06 msec (n = 28) indicates that depressed LVEF (< 55%) is nearly as reliable as the R peak delay in V 6 (sensitivity, 51.7%; specificity, 88.5%; positive predictive value, 75.6%; predictive accuracy, 73.5%). Thus, the criteria are useful indicators of reduced LVEF, which could reflect either abnormally high systolic wall stress or decreased myocardial contractility.