Evaluation of the Left Ventricular Hemodynamic Derangements Due to Ventricular Premature Contractions by Pulsed Doppler Echocardiography

Abstract

The purpose of this study was to evaluate left ventricular (LV) hemodynamic changes due to ventricular premature contractions (VPCs). The study population consisted of 45 patients with VPCs, 26 men and 19 women, aged 11-78 years. All VPCs studied were monomorphic with a compensatory pause; bigeminy was excluded. To evaluate LV hemodynamic changes due to VPCs, the stroke volume of VPC and the first postextrasystolic beat and the filling volume of the beat preceding VPC were measured by planimetrie integration of Doppler LV outflow and inflow velocity recordings and expressed as the percent stroke and filling volume of a control sinus beat, respectively. The relative contribution of left atrial contraction to LV filling volume was calculated as the flow velocity integral during the left atrial ejection phase divided by the integral of the total LV filling period of a basic sinus beat. The percent filling volume of the beat preceding VPC showed a significant correlation with the coupling interval. However, the percent stroke volume showed this correlation only in patients with a small atrial contribution to ventricular filling. Postextrasystolic increase in percent stroke volume was larger in VPCs with a shorter coupling interval, but the augmentation of this increase was less sufficient in patients with a smaller atrial contribution to ventricular filling. In patients with a large atrial contribution to ventricular filling, no significant correlation was observed between the coupling interval and the percent stroke volume of VPC or postextrasystolic beat. These findings suggest that the hemodynamic effect of VPCs was affected mainly by decrease in preload and also by LV diastolic properties in individual patients.