Correlations between electrocardiographic, vectorcardiographic, and echocardiographic findings in patients with left ventricular overload

Abstract

Summary Left ventricular echocardiography was employed to assess the vectorcardiographic and electrocardiographic manifestations of left ventricular hypertrophy with or without dilatation. Based upon their echocardiographic and hemodynamic findings, 97 subjects were divided into four groups; 40 patients with left ventricular hypertrophy (LVH), 26 patients with left ventricular dilatation (LVD), 17 patients with aortic regurgitation (AR), and 14 patients with mitral regurgitation (MR). Left ventricular wall thickness, the sum of the thickness of the ventricular septum and posterior wall, correlated well with spatial maximum QRS magnitude (r=0.67) and SV 1 + RV 5 or V 6 (r=0.85) in LVH. On the other hand, dilatation of the left ventricle seemed to play an important role in the augmented QRS voltage in LVD, AR, and MR. A significant correlation was observed between left ventricular diameter at end-diastole (LV diastolic diameter) and QRS interval in LVD, AR, and MR. LV diastolic diameter also correlated with Rx peak time in LVD, Rx and Ry peak times in AR and Ry and Rz peak times in MR. In addition, horizontal QRS configuration was affected by left ventricular dilatation. In LVD and AR, the incidence of a figure-of-8 or clockwise configuration increased in cases with LV diastolic diameter ≥6.5 cm. Thus, left ventricular dilatation was demonstrated to be responsible for prolongation of QRS interval. In LVD and AR, it could induce delay of Rx peak time and consequently QRS loop deformity in the horizontal plane.