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 baseline 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.