Systemic and regional haemodynamic effects of aortofemoral angiography

The aim was to investigate the regional and systemic haemodynamic consequen ces of bolus injection of fluids with different physical properties in the course of routine aortography. Iopamidol was compared with an equiosmolar s olution of mannitol and with a 0.9 N saline solution. Continuous blood flow and Pulsatility Index (PI), as an index of regional vascular resistance, w ere measured by Doppler technique. Finger arterial pressure and heart rate were monitored at the time and for 3 min following each intraaortic bolus i njections. The patients who underwent routine aortography were grouped acco rding to the site of the flow measurements: common femoral artery, common c arotid artery and brachial artery. Flow changes induced by the bolus infusi on were evident for all the fluids but only at the femoral artery level. Af ter an immediate (3 +/- 2 s) and brief (2 +/- 2 s) but marked reduction of flow and in-phase increase of PI following the bolus, further haemodynamic changes were observed only in the femoral artery, with a peak at 35 +/- 10 s and returning to baseline values after 70 +/- 15 a, in terms of both incr eased mean blood velocity and decreased PI. Saline and mannitol induced ove rall blood velocity alterations of 54% and 80%. respectively, and PI reduct ions of 44%;, and 57% compared with those induced by iopamidol. In the othe r vascular areas there was only a 17+/-2% increase of the physiological ear ly diastolic backflow at the brachial artery level. Blood pressure decrease d and heart rate increased in phase with the flow changes of the femoral ar tery. In conclusion: (1) a dramatic rheodynamic perturbation at the site of injection induces a vasodilating stimulus; (3) the haemodynamic response f ollowing injection results in marked vasodilation of only the tributary vas cular bed; (3) flow steal may occur from other beds towards the lower limb vascular beds owing to vascular impedance imbalance; (4) a reduction of sys temic arterial pressure is induced in phase with the regional vascular even ts and a reflex increase of the heart rate; and (5) the physical properties of the injected fluids influence the intensity of the perturbation, althou gh the decisive triggering factor is the counterflowing bolus per sc.