Diagnostic implications of figure-of-eight and clockwise QRS loop rotation on the horizontal vectorcardiogram in chronic aortic valve disease

Left ventricular function-conduction impairment as reflected by the ECG in chronic aortic regurgitation

The study was conducted to ascertain that the ECG assists in the assessment of systolic dysfunction in chronic aortic regurgitation. Five variables were reviewed in 146 adults without bundle branch block who underwent angiocardiography: total 12-lead QRS amplitude, QRS duration, maximum R peak time in I, V5 or V6, maximum R peak time relative to S peak time of the maximum S in V1, V2 or V3, and maximum T wave amplitude and polarity in I, V6 or aVF. In order to define which of them could differentiate left ventricular ejection fraction (EF) ≥50% (n = 101) from EF <50% (n = 45) they were subjected to stepwise linear discriminant analysis. The maximum R peak time relative to S peak time emerged as the most promising variable. In predicting EF <50%, R peak time prolongation exceeding S peak time, i.e. R peak delay, yields reliable results, with specificity, positive and negative predictive value being 89.1%, 70.3% and 82.6%, respectively, and sensitivity being 57.8%. As given by the sample odds-ratio, R peak delay indicates an 11-fold increased risk of having EF <50%. R peak delay, a marker of left ventricular function-conduction impairment identifies patients who need valve replacement.

Electrocardiographic markers of impaired left ventricular ejection performance in aortic stenosis

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 V6 to the S peak in V2; and (2) the negative P wave terminal force in V1 (Morris index, n = 109). Left ventricular ejection fraction (LVEF) was significantly depressed in patients with the R peak in V6 later than the S peak in V2 (R peak delay in V6, n = 24), compared with those with the R peak in V6 preceding the S peak in V2 or with both peaks occurring simultaneously (n = 97) (LVEF 40.8 +/- 11.8% vs 69.9 +/- 13.3%, p = .000). LVEF less than 55% was present in 87.5% of patients with the R peak delay in V6 and in only 23.7% of those without this finding. The Morris Index was significantly greater in patients with LVEF less than 55% (n = 39) than in those with LVEF greater than or equal to 55% (n = 70) (Morris Index 0.063 +/- 0.035 msec vs 0.030 +/- 0.025 msec, p = .000). The R peak delay in V6 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.(ABSTRACT TRUNCATED AT 250 WORDS)