Effect of chronic beta-blockade on QT interval in patients with liver cirrhosis.
OBJECTIVE
QT interval prolongation is frequent in cirrhosis, predicts a poor prognosis and may trigger severe ventricular arrhythmias. Our aim was to evaluate the effect of chronic beta-blockade on QT prolongation.


METHODS
Clinical and laboratory evaluation, ECG and hepatic vein pressure gradient (HVPG) measurement were performed in 30 cirrhotic patients before and 1-3 months after prophylactic nadolol. QT was corrected for heart rate by the cirrhosis-specific formula and other formulas.


RESULTS
QT(cirrhosis) was prolonged in 10 patients (33%); HVPG was increased in all cases. QT(cirrhosis) was correlated with the Child-Pugh score (r=0.40; p=0.027). Nadolol shortened QT interval only with the Bazett formula (p=0.01), remaining unchanged with the other formulas. The QT interval shortened only if prolonged at baseline (from 473.3+/-5.5 to 458.4+/-6.5 ms; p=0.007), while it lengthened when normal (from 429.8+/-3.1 to 439.3+/-2.9 ms; p=0.01). QTc changes were directly related to the baseline value (p<0.001). HVPG decreased from 19.4+/-0.8 to 15.6+/-1.3 mmHg (p=0.004). The HVPG changes did not correlate with QTc changes.


CONCLUSIONS
Chronic beta-blockade shortens the QT interval only in patients with prolonged baseline values, and this is likely due to a direct cardiac effect.
Zambruni
Andrea
A
Dipartimento di Medicina Interna, Cardioangiologia, Epatologia, Semeiotica Medica, Alma Mater Studiorum, Università di Bologna, Bologna, Italy. azambruni@hotmail.com
Trevisani
Franco
F
Di Micoli
Antonio
A
Savelli
Francesco
F
Berzigotti
Annalisa
A
Bracci
Eleonora
E
Caraceni
Paolo
P
Domenicali
Marco
M
Felline
Palmiro
P
Zoli
Marco
M
Bernardi
Mauro
M
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology* / Q000627:therapeutic use; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D001794:Blood Pressure / Q000502:physiology; D004562:Electrocardiography; D004932:Esophageal and Gastric Varices / Q000150:complications; D005260:Female; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006470:Hemorrhage / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D006503:Hepatic Veins / Q000502:physiology; D006801:Humans; D008103:Liver Cirrhosis / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009248:Nadolol / Q000494:pharmacology* / Q000627:therapeutic use; D011379:Prognosis; D012307:Risk Factors; D016276:Ventricular Function / Q000187:drug effects
D000319:Adrenergic beta-Antagonists; D009248:Nadolol