Effects of nitroglycerine on cerebral blood flow velocity, quantitative electroencephalogram and cognitive performance

Background Despite the widespread use of nitroglycerine, little is known of its cerebral haemodynamic effects. The present study was undertaken to eva luate the effects of nitroglycerine on cerebral circulation and cognitive f unction in normal volunteers. Design Twelve healthy male volunteers (age 35 +/- 3 years; mean +/- SD) rec eived continuous intravenous infusions of nitroglycerine at 1 mg h(-1) and 2 mgh(-1) rates as well as placebo (0.9% saline) under randomized, double-b lind cross-over conditions on three different occasions. A 10-min quantitat ive EEG (qEEG) was recorded before, during and repeatedly after infusion. B lood flow velocity in the left arteria cerebri media (MCA) was measured sim ultaneously by means of transcranial Doppler sonography. Cognitive performa nce was assessed with a computerized test battery. Results Administration of nitroglycerine caused a significant reduction of mean blood flow velocity in the left MCA. Ln parallel a significant increas e of absolute power density <4 Hz was noted. The latter effect was dose dep endent. Cognitive functions, such as attention and memory, were not altered . Conclusions The decrease in cerebral blood flow velocity in the left MCA ma y be due to vasodilatation and/or reduction in perfusion. The concomitant i ncrease of slow wave power in the qEEG may indicate an impairment of brain function.