QT interval prolongation and decreased heart rate variability in cirrhotic patients: relevance of hepatic venous pressure gradient and serum calcium.
A prolongation of QT interval has been shown in patients with cirrhosis and it is considered as part of the definition of the so-called 'cirrhotic cardiomyopathy'. The aim of the present study was to assess the determinants of QT interval prolongation in cirrhotic patients. Forty-eight male patients with different stages of liver disease were divided into three subgroups according to the Child-Pugh classification. All patients underwent a 24-h ECG Holter recording. The 24-h mean of QT intervals corrected for heart rate (termed QTc) and the slope of the regression line QT/RR were calculated. HRV (heart rate variability), plasma calcium and potassium concentration and HVPG (hepatic venous pressure gradient) were measured. QTc was progressively prolonged from Child A to Child C patients (P=0.001). A significant correlation between QTc and HVPG was found (P=0.003). Patients with alcohol-related cirrhosis presented QTc prolongation more frequently than patients with post-viral cirrhosis (P<0.001). The QT/RR slope was steeper in subjects with alcoholic aetiology as compared with viral aetiology (P=0.02), suggesting that these patients have a further QTc prolongation when heart rate decreases. The plasma calcium concentration was inversely correlated with QTc (P<0.001). The presence of severe portal hypertension was associated with decreased HRV (P<0.001). Cirrhotic patients with a more severe disease, especially of alcoholic aetiology, who have greater HVPG and lower calcium plasma levels, have an altered ventricular repolarization and a reduced vagal activity to the heart, which may predispose to life-threatening arrhythmias.
Genovesi
Simonetta
S
Department of Clinical Medicine and Prevention, University of Milano-Bicocca, via Cadore 48, Monza 20052, Italy. simonetta.genovesi@unimib.it
Prata Pizzala
Daniela M
DM
Pozzi
Massimo
M
Ratti
Laura
L
Milanese
Maria
M
Pieruzzi
Federico
F
Vincenti
Antonio
A
Stella
Andrea
A
Mancia
Giuseppe
G
Stramba-Badiale
Marco
M
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D002118:Calcium / Q000378:metabolism; D009202:Cardiomyopathies / Q000000981:diagnostic imaging; D004452:Echocardiography; D015716:Electrocardiography, Ambulatory; D006801:Humans; D008103:Liver Cirrhosis / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D008133:Long QT Syndrome / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D017082:Portal Pressure / Q000502:physiology
D002118:Calcium