HEMODYNAMIC-EFFECTS OF ACETAZOLAMIDE IN PATIENTS WITH CARDIOVASCULAR DISORDERS - CORRELATION WITH CALCULATED CEREBRAL PERFUSION RESERVE

Individual responses of cerebral blood flow to acetazolamide are highl y variable. We hypothesized that this may be due to interactions with cardiovascular diseases and medication. Therefore, we measured the hae modynamic effects of acetazolamide in patients with various cardiovasc ular disorders and evaluated whether these had any correlation with ca lculated cerebral perfusion reserve. Ten male patients aged 58 +/- 9 y ears (mean+/-S.D.) were studied with first-pass radionuclide ventricul ography and echocardiography before and 20 min after the administratio n of 1 g acetazolamide. Systolic blood pressure fell from 133 +/- 21 t o 128 +/- 19 mmHg (P < 0.05) and the cardiac output to total blood vol ume ratio increased from 0.85 +/- 0.18 to 0.92 +/- 0.11 (P = 0.05), in dicating a 14% reduction in peripheral vascular resistance. In a furth er study, 15 patients aged 60 +/- 7 years (22 studies) were studied si multaneously with a nuclear stethoscope and Tc-99(m)-hexamethylpropyle neamine oxime single photon emission tomography before and after aceta zolamide administration. The cardiac output ratio increased from 0.81 +/- 0.17 to 0.89 +/- 0.17 (P < 0.05) and showed a significant inverse correlation with calculated cerebral perfusion reserve. In conclusion, acetazolamide increases the cardiac output ratio and reduces systolic blood pressure, indicating reduced peripheral vascular resistance in patients with various cardiovascular diseases and medication. The incr ease in the cardiac output ratio is inversely related with calculated cerebral perfusion reserve. This helps to explain the high individual variability in calculated cerebral perfusion reserve.