Narcolepsy, cataplexy, heart rate, and blood pressure.

Seven narcoleptic patients had serial measurements of blood pressure taken during nocturnal sleep over a period of 2 or 3 successive nights. Blood pressure was measured using a Doppler system with a cuff that automatically inflates every 15 min. There was no difference in the blood pressure measurements throughout the night compared with normal control subjects. Blood pressure followed the patterns of normal nocturnal variation; there was a nonsignificant increase in REM sleep compared with stage 3-4 NREM sleep. Studies of heart rate immediately preceding cataplectic attacks were inconclusive in identifying cardiovascular changes preceding muscle weakness.