Acute non-selective beta-adrenergic blockade reduces prolonged frequency-adjusted Q-T interval (QTc) in patients with cirrhosis.
OBJECTIVE
Earlier studies have shown a prolonged frequency-adjusted Q-T interval (QTc>0.440 s(1/2)) in a substantial fraction of patients with cirrhosis. The effect of beta-blockade on QTc is unknown, and its determination was the aim of the study.


METHODS
Seventeen patients with cirrhosis received 80 mg propranolol orally during a haemodynamic investigation with measurements at baseline and 90 min after propranolol ingestion.


RESULTS
Beta-blockade reduced cardiac output (-21%, P<0.001), heart rate (-20%, P<0.001), and the hepatic venous pressure gradient (HVPG, -17%, P<0.02). The mean QTc=0.460 s(1/2) was prolonged compared to 0.410 s(1/2) in age-matched controls (P<0.01). Whereas QTc decreased during beta-blockade in the cirrhotic patients (from 0.460 to 0.440 s(1/2), P<0.01), no effect was found in the subgroup with normal QTc (0.429 vs. 0.422 s(1/2), ns), and a reduction was seen in the patients with prolonged QTc (from 0.488 to 0.456 s(1/2), P<0.01). The percentage decrease in QTc was related to the reduction in HVPG (r=0.48, P=0.03) and cardiac output (r=0.56, P=0.02).


CONCLUSIONS
Acute non-selective beta-blockade reduces prolonged QTc towards normal values in patients with cirrhosis. The clinical significance of QTc reduction in arrhythmia is a topic for future research.
Henriksen
Jens H
JH
Department of Clinical Physiology, University of Copenhagen, 239, Hvidovre Hospital, DK-2650 Hvidovre, Denmark. jens.h.henriksen@hh.hosp.dk
Bendtsen
Flemming
F
Hansen
Erik Feldager
EF
Møller
Søren
S
D000284:Administration, Oral; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage*; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008104:Liver Cirrhosis, Alcoholic / Q000150:complications*; D008133:Long QT Syndrome / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D011433:Propranolol / Q000008:administration & dosage*; D014655:Vascular Resistance / Q000187:drug effects
D000319:Adrenergic beta-Antagonists; D011433:Propranolol