Cardiovascular changes in cluster headache

Five patients suffering from cluster headache underwent simultaneous recordings of the pneumogram, ECG, and systemic arterial pressure before and during attacks. The polygraphic investigations showed the following: systolic and diastolic blood pressure increased during attacks; mean heart rate decreased or increased; mean respiratory rate decreased or remained unchanged. Standard deviations and coefficients of variation of all three measures calculated during attacks were higher than those recorded before attacks. The polygraphic recordings showed that during attacks there were phasic cardiovascular changes characterized by an increase and subsequent decrease in arterial pressure and heart rate, synchronous with the respiratory movements. Cardiovascular reflex function was assessed in two patients prior to and during attacks: Valsalva maneuver was normal before and during attacks; beat-to-beat variation of heart rate and heart rate variability during deep breathing showed higher values during attacks compared with values beforehand. The findings of this study suggest a central disturbance of vagus-sympathetic equilibrium.