FLOW-MEDIATED ARTERIAL DILATION IS ABNORMAL IN CONGESTIVE-HEART-FAILURE

Background. Abnormalities in endothelium-dependent relaxation to acety lcholine have been reported in congestive heart failure (CHF). The pur pose of this study was to determine whether there are abnormalities in flow-mediated large vessel relaxation in patients with chronic CHF. M ethods and Results. The dilator response of the radial artery was meas ured by a new high precision A-mode ultrasound device in response to r elease of 10 minutes of forearm arterial occlusion (reactive hyperemic blood flow response, RHBF). Radial arterial blood velocity was measur ed simultaneously, and blood flow was calculated. In nine patients wit h chronic CHF, there was a small but insignificant reduction of peak R HFB (p=0.09) when compared with nine age-matched control subjects. The increase in arterial diameter that followed the peak blood flow was s ignificantly reduced in CHF (normal: 14.98+/-247%; CHF: 7.58+/-0.89%; p<0.01). In addition, the time to peak arterial relaxation was delayed (normal: 57.8+/-9.4 seconds; CHF: 98.9+/-15 seconds; p<0.02). When th e peak percent increase in diameter was divided by the magnitude of th e peak blood flow response, differences in the CHF and normal groups p ersisted. Conclusions. These data indicate that flow-mediated large ar tery relaxation is abnormal in CHF. It is suggested that both structur al and endothelium-dependent abnormalities may contribute to this abno rmal response.