Hemodynamic effects of chronic hemodialysis therapy assessed by pulse waveform analysis

Cardiovascular responses to hemodialysis have been characterized by invasive monitoring techniques. These techniques are not feasible for evaluation of hemodynamic status during dialysis in the outpatient setting. In this study, we used pulse waveform analysis (PWA), a noninvasive tool designed for the ambulatory setting, to assess hemodynamic responses of dialysis treatments in 27 stable subjects with end-stage renal disease receiving chronic hemodialysis. In our population, systolic, diastolic, and pulse pressures were unaffected by dialysis despite the mean fluid removal of 3.0 +/- 0.2 kg. However, using PWA, we observed that stroke volume and cardiac output progressively declined by 17% to 19% (P <.001) with a concomitant increase in systemic vascular resistance by 22% from 1654 +/- 88 to 2020 +/- 121 dynes. sec. cm(-5) (P <.001). Also, we observed a significant reduction in small artery compliance from 4.7 +/- 0.5 to 3.3 +/- 0.4 mL. mm Hg(-1). 100 (P =.01), whereas large artery elasticity was unaffected. These findings suggest that changes in small artery vascular compliance contribute to the elevation in systemic vascular resistance during dialysis. This study confirms that hemodynamic adaptations to the dialysis procedure can be detected using PWA and are consistent with data obtained by invasive monitoring techniques. Furthermore, the observed reduction in vascular compliance in response to dialysis may contribute to the high cardiovascular risk in patients undergoing chronic hemodialysis therapy.