Spatial quantitative vectorcardiography in aortic stenosis: correlation with hemodynamic findings

Thirty-four patients with hemodynamically documented valvar aortic stenosis without congestive heart failure were studied by the corrected Frank lead system vectorcardiography, with special emphasis on the angular characteristics of spatial R max to define the severity of the lesion. Spatial QRS-T angle demonstrated a highly significant correlation with the peak left ventricular systolic pressure (r = 0.72, P < 0.001) and a significant correlation with peak transvalvar aortic gradient (r = 0.49, P < 0.01). Furthermore, all patients with a QRS-T angle of more than 90° had significant aortic stenosis (TVG ≥ 50 mm Hg). The peak left ventricular systolic pressure and transvalvar aortic gradient also demonstrated a significant negative correlation with azimuth angle (r = -0.36 and -0.34, respectively; P < 0.05) and a positive correlation with spatial R max magnitude (r = 0.38 and 0.41, respectively; P < 0.05). There was no correlation between elevation angle of spatial R max and left ventricle systolic pressure or transvalvar aortic gradient. Our study indicates that spatial quantitative vectorcardiographic angular characteristics, particularly spatial QRS-T angle, may be a useful adjunct to other noninvasive techniques to assess the severity of valvar aortic stenosis.