Reduced cardio-respiratory coupling in acute alcohol withdrawal.
BACKGROUND
Chronic alcoholism represents a risk factor for cardiac arrhythmias. One underlying mechanism is a sympathetically dominated autonomic imbalance. This is especially apparent during acute withdrawal from alcohol. Since linear analysis of heart rate variability may not be entirely adequate to detect such autonomic dysfunction in acute alcohol withdrawal, we applied novel non-linear parameters and measures for cardio-respiratory coupling.


METHODS
20 patients suffering from acute alcohol withdrawal syndrome and 20 controls were included. For patients, heart rate and respiration were recorded on admission, after medication and at discharge. From these data, complexity measures (symbolic dynamics, approximate entropy) of heart rate modulation and respiration as well as parameters for cardio-respiratory coupling (coherence, cross-approximate entropy) which relate to vagal function were calculated.


RESULTS
Heart rate modulation was significantly less complex in patients acutely admitted for alcohol withdrawal. Furthermore, coupling between beat-to-beat (RR) intervals and respiration time series was significantly diminished. Of the parameters assessed, cross-approximate entropy showed a trend for correlation with symptom severity.


CONCLUSIONS
These data indicate diminished vagal function in acute alcohol withdrawal. Applying the methods described thus allows a sensitive detection of vagal neuropathy in this disease.
Bär
Karl-Jürgen
KJ
Department of Psychiatry, Friedrich-Schiller-University, Philosophenweg 3, Jena, Germany. Karl-Juergen.Baer@med.uni-jena.de
Boettger
Michael Karl
MK
Schulz
Steffen
S
Neubauer
Rene
R
Jochum
Thomas
T
Voss
Andreas
A
Yeragani
Vikram K
VK
D000328:Adult; D000437:Alcoholism / Q000523:psychology; D000465:Algorithms; D002320:Cardiovascular Physiological Phenomena / Q000187:drug effects*; D002492:Central Nervous System Depressants / Q000009:adverse effects*; D002719:Chlormethiazole / Q000627:therapeutic use; D019277:Entropy; D000431:Ethanol / Q000009:adverse effects*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006993:Hypnotics and Sedatives / Q000627:therapeutic use; D008297:Male; D015999:Multivariate Analysis; D011569:Psychiatric Status Rating Scales; D015656:Respiratory Mechanics / Q000187:drug effects*; D013375:Substance Withdrawal Syndrome / Q000188:drug therapy / Q000503:physiopathology*; D014630:Vagus Nerve / Q000503:physiopathology
D002492:Central Nervous System Depressants; D006993:Hypnotics and Sedatives; D002719:Chlormethiazole; D000431:Ethanol