Electrocardiographic Versus Echocardiographic Left Ventricular Hypertrophy in Severe Aortic Stenosis

Abstract

Although ECG used to be a traditional method to detect left ventricular hypertrophy (LVH), its importance has decreased over the years and echocardiography has emerged as a routine technique to diagnose LVH. Intriguingly, an independent negative prognostic effect of the "electrical" LVH (i.e., by ECG voltage criteria) beyond echocardiographic LVH was demonstrated both in hypertension and aortic stenosis (AS), the most prevalent heart valve disorder. Our aim was to estimate associations of the ECG-LVH voltage criteria with echocardiographic LVH and indices of AS severity. We retrospectively manually analyzed ECG tracings of 50 patients hospitalized in our center for severe isolated aortic stenosis, including 32 subjects with echocardiographic LVH. The sensitivity of single traditional ECG-LVH criteria in detecting echocardiographic LVH was 9-34% and their respective specificity averaged 78-100%. The ability to predict echocardiographic LVH was higher for S-waves than R-waves (mean area under the receiver operating curve (AUC): 0.62-0.70 vs. 0.58-0.65). Among combinations of R- and S-waves, the discriminating ability was highest for the Cornell voltage (AUC: 0.71) compared to the Sokolow-Lyon, Romhilt and Gubner-Ungerleider voltage (AUC: 0.62-0.68). By multiple regression, peak aortic pressure gradient was positively related to the Sokolow-Lyon (β = 1.7 ± 0.5, p = 0.002) and Romhilt voltage (β = 1.3 ± 0.5, p = 0.01), but not Cornell (0.5 ± 0.3, p = 0.2) or Gubner-Ungerleider voltage (β = 0.0 ± 0.5, p > 0.9), regardless of LV mass index. In conclusion, echocardiographic LVH and stenosis severity appear to have distinct associations with traditional ECG-LVH criteria in AS. A moderate diagnostic superiority of the Cornell voltage criterion with regard to anatomic LVH might result from its unique ability to include depolarization vectors in both the frontal and horizontal plane with consequent lesser sensitivity to the confounding effect of obesity.

Keywords: aortic stenosis; echocardiography; electrocardiography; left ventricular hypertrophy.

Figure 1

Discriminating ability of the voltage of the R-wave and S-wave in single precordial leads (A), single limb leads (B), and combinations of the amplitude of R-waves and S-waves (C) for the prediction of echocardiographic LVH according to the receiver operating characteristic (ROC) curve analysis. p-values below 0.05 are denoted in bold.