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.