Autonomic regulation of heart rate and QT interval in nonalcoholic cirrhosis with ascites.
OBJECTIVE
Autonomic neuropathy, as indicated by alterations in standard cardiovascular tests, is frequently encountered in cirrhosis. We investigated the autonomic modulation of the heart in nonalcoholic cirrhosis with ascites by evaluating the 24-hour heart rate variability (HRV), a powerful noninvasive tool to assess the sympathovagal balance of the heart.


METHODS
Low (LF) and high frequency (HF) components and their ratio, and time domain indexes of HRV were evaluated in 24-hour, daytime and nighttime periods in 12 patients and 12 healthy subjects, together with the conventional and dynamic QT interval.


RESULTS
Cirrhotic patients had values of the mean RR interval and frequency domain indexes in the whole 24-hour period similar to those of healthy subjects, despite higher than normal plasma norepinephrine levels. Patients also showed lower LF and higher HF values than controls during the day, a reduction in time domain indexes, and no circadian rhythm of frequency domain indexes. QT parameters were similar in the 2 groups, but patients had a blunted QT rhythm and a reduced QT variability.


CONCLUSIONS
Patients with nonalcoholic cirrhosis and ascites have an impaired autonomic regulation of the heart, which involves both the sympathetic and the parasympathetic branches of the autonomic nervous system.
Lazzeri
C
C
Istituto di Medicina Interna, University of Florence School of Medicine, Italy.
La Villa
G
G
Laffi
G
G
Vecchiarino
S
S
Gambilonghi
F
F
Gentilini
P
P
Franchi
F
F
D000368:Aged; D000369:Aged, 80 and over; D001201:Ascites / Q000503:physiopathology*; D001341:Autonomic Nervous System / Q000503:physiopathology*; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D008103:Liver Cirrhosis / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D013997:Time Factors
D009638:Norepinephrine