The effect of isosorbide dinitrate, a donor of nitric oxide, on maternal cerebral blood flow in gestational hypertension and preeclampsia

OBJECTIVE: The purpose of this study was to investigate the effect of a nitric oxide donor on cerebral perfusion pressure and other blood flow index values in the maternal middle cerebral and basilar arteries. STUDY DESIGN: Sublingual tablets of 5-mg isosorbide dinitrate were administered to 19 hypertensive pregnant patients. Doppler velocimetry of the middle cerebral and basilar arteries was obtained with a transcranial Doppler with the use of the transtemporal and suboccipital approach. RESULTS: The mean (±SEM) flow velocity in the middle cerebral artery significantly decreased from a baseline of 65.9 ± 3.1 cm/s to 55.2 ± 2.2 and 52.0 ± 2.1 cm/s at 10 and 20 minutes ( P < .0001). Resistance area product insignificantly increased from a baserine of 2.0 ± 0.1 before isosorbide dinitrate to 2.19 ± 0.11 at 20 minutes. No significant changes were observed in the resistance and pulsatility indices in the middle cerebral artery. The cerebral perfusion pressure did not change significantly after isosorbide dinitrate (84.5 ± 7.3, 80.8 ± 6.6, and 78.5 ± 5.0 mm Hg at 0, 10, and 20 minutes, respectively) nor did the cerebral blood flow index. CONCLUSION: The results obtained demonstrate that cerebral perfusion pressure is unaltered by isosorbide dinitrate, despite significant changes in maternal blood pressure and in blood flow velocities in the middle cerebral artery.