DOBUTAMINE EFFECT ON ANKLE-BRACHIAL PRESSURE INDEX IN PATIENTS WITH PERIPHERAL ARTERIAL OCCLUSIVE DISEASE - NEW NONINVASIVE TEST FOR EVALUATION OF PERIPHERAL-CIRCULATION

Background. This study was designed to evaluate the effect of short-te rm administration of graded dose of dobutamine on the circulation of t he lower limbs in the patients with symptomatic peripheral arterial oc clusive disease. Methods. An ankle-brachial pressure index (ABI) was d etermined at the time of dobutamine stress echocardiography by measuri ng systolic pressure over the brachial artery and right dorsalis pedis artery using continuous-wave Doppler instrument. Setting. The study w as conducted on all patients who had dobutamine stress echocardiograph y ordered by their referring physicians and performed in the Echocardi ography Laboratory of the Mayo Clinic. Patients. All patients schedule d for dobutamine stress echocardiography were the subject of this stud y unless they had rigid vessels defined as ABI > 1.5, were on beta-blo kers or did not agree to participate in the study. 20 patients, mean a ge 67+/-9 years (9 men and 11 women) without peripheral occlusive arte rial disease and resting ABI greater than or equal to 1.0 (group A), a nd 18 patients, mean age 71+/-10 years (11 men and 7 women) with the e vidence of peripheral occlusive arterial disease and ABI <1.0 were exa mined. Measures. ABI was measured just prior to starting the dobutamin e infusion, and then at the third minute of each increment in dobutami ne dosage. Results. In control group patients ABI rises at 5-10 mu g/k g/min of dobutamine infusion and at higher doses (20-50 mu g/kg/min) d rops back to the baseline values. In the patients with peripheral arte rial occlusive disease low doses of dobutamine do not increase ABI, bu t higher doses cause decrease of pressure index from 0.6 to 0.3. There was no incidence of ischemic pain or any other kind of discomfort in the lower extremities. Conclusions. Low doses of dobutamine have no de cremental effect on peripheral circulation. High doses of dobutamine c ause a profound decrease of blood pressure in the lower Limbs of patie nts with peripheral occlusive arterial disease, and the extent of decr ease was proportional to the degree of ischemia. Peripheral blood pres sure changes registered in the study over dorsalis pedis artery at the time of dobutamine infusion resemble those that occurred at the time of exercise-walking test. ABI measurement at the time of dobutamine ec hocardiography might be a useful test for the evaluation of peripheral circulation. Further studies are necessary for the assessment of a cl inical usefulness of dobutamine-ankle-brachial test.