EFFECTS OF CHRONIC THERAPY WITH NADOLOL ON PORTAL HEMODYNAMICS AND ONSPLANCHNIC IMPEDANCE INDEXES USING DOPPLER SONOGRAPHY - COMPARISON BETWEEN ACUTE AND CHRONIC EFFECTS

Background/Aims: Beta-blockers are currently used for chronic therapy of portal hypertension. Duplex Doppler ultrasonography has been propos ed for non-invasive evaluation of splanchnic pharmacodynamics, but the chronic effects of beta-blockers on portal hemodynamics and on splanc hnic arterial impedance indices have not been analyzed with this metho d. This was the aim of the study. Methods: The effects of acute (80 mg p.o.) and chronic (2 months at a dosage sufficient to reduce heart ra te by at least 25% in respect of basal values) nadolol administration on portal blood flow velocity and volume, and on splanchnic and renal arterial impedance indices [pulsatility index=(peak systolic velocity- minimum velocity)/mean velocity] were evaluated in patients with cirrh osis. Twenty-eight patients with cirrhosis and portal hypertension wer e investigated. Nineteen patients received nadolol, and nine received placebo. Results: Placebo caused no significant hemodynamic change, Po rtal blood flow mean velocity decreased after chronic therapy (11.7+/- 2.9 cm/s to 9.1+/-2.3, p<0.001). In the 16 patients with acute and chr onic evaluation, portal blood flow mean velocity decreased after acute therapy (11.8+/-3.0 cm/s to 10.4+/-3.0, p<0.01), and even more so aft er chronic therapy (to 9.2+/-2.4, p<0.01). No parallel was found betwe en acute and chronic effects. Hepatic, mesenteric and splenic pulsatil ity indices increased after chronic therapy (1.26+/-0.33 to 1.39+/-0.2 8, p<0.02; 2.04+/-0.41 to 2.50+/-0.61, p<0.01; 0.92+/-0.22 to 1.18+/-0 .27, p<0.001 respectively); renal pulsatility index increased (1.12+/- 0.20 to 1.40+/-0.28, p<0.001). Conclusions: Chronic therapy with nadol ol decreased portal blood flow velocity and volume, and increased spla nchnic and renal impedance indices. Chronic effects of nadolol on port al inflow cannot be predicted from its acute effects, Evaluation of th e effect of nadolol on portal blood velocity and volume should be perf ormed after chronic therapy, Duplex Doppler ultrasonography allows ven ous and arterial splanchnic pharmacodynamics to be studied separately.