THE EFFECT OF VERAPAMIL CALCIUM-ANTAGONIST ON AUTONOMIC IMBALANCE IN MIGRAINE - EVALUATION BY SPECTRAL-ANALYSIS OF BEAT-TO-BEAT HEART-RATE FLUCTUATIONS
M. Zigelman et al., THE EFFECT OF VERAPAMIL CALCIUM-ANTAGONIST ON AUTONOMIC IMBALANCE IN MIGRAINE - EVALUATION BY SPECTRAL-ANALYSIS OF BEAT-TO-BEAT HEART-RATE FLUCTUATIONS, Headache, 34(10), 1994, pp. 569-577
Abnormalities in autonomic control have been documented in migraine ev
en during the headache-free interval. It has long been recognized that
spectral analysis of heart rate (HR) fluctuations can reflect the aut
onomic function, especially the sympathetic to parasympathetic balance
. This technique is the basis for a quantitative approach to the inves
tigation of migraine applied in the present study. A 24-hour Holter EC
G recording was performed for each subject in a group of five migraine
patients during the inter-headache period. In addition, shorter 5-min
ute-long recordings of blood flow (BF) and blood pressure (BP) were ma
de in these patients in both supine and standing positions. Short, 256
-second subtraces were taken every 30 minutes along the 24-hour ECG si
gnal and were submitted, as well as the BF and BP traces. to A/D conve
rsion and computation of the power spectrum of fluctuations in HR, BF,
and BP. Spectral analysis of fluctuations in these hemodynamic parame
ters was performed in the migraine patients before and during the trea
tment with verapamil and compared to that of a healthy control group.
This procedure enabled us to assess the autonomic function. the sympat
hetic vs parasympathetic balance, and their response to a change in po
sition, before and during calcium blockade. A characteristic autonomic
abnormality is revealed in the group of untreated migraine patients i
n supine position: enhanced low frequency (LF) fluctuations reflecting
increased sympathetic sensitivity during the inter-headache phase. An
exaggerated sympathetic response is measured in the migraine patients
during the transition from supine to standing position with a concomi
tant nonsignificant decrease in parasympathetic response. Under the in
fluence of verapamil, the enhancement in low frequency fluctuations is
reversed as well as the exaggerated sympathetic response to standing.