Korean J Anesthesiol.  2014 Mar;66(3):199-203. 10.4097/kjae.2014.66.3.199.

Alteration of the QT variability index in end-stage liver disease

• Huh IY
• Park ES
• Kim KI
• Lee AR
• Hwang GS

• KMID: 2092445
• DOI: http://doi.org/10.4097/kjae.2014.66.3.199

Abstract

BACKGROUND
A prolonged QT interval can lead to malignant ventricular arrhythmias and sudden cardiac death, and has frequently been found in end-stage liver disease (ESLD). However, myocardial repolarization lability has not yet been fully investigated. We evaluated the QT variability index (QTVI), a marker of temporal inhomogeneity in ventricular repolarization and an abnormality associated with re-entrant malignant ventricular arrhythmias. We determined whether QTVI is affected by the head-up tilt test in ESLD.
METHODS
We assessed 36 ESLD patients and 12 control subjects without overt heart disease before and after the 70-degree head-up tilt test. The electrocardiography signal (lead II) was recorded on a computer with an analog-to-digital converter. The RR interval (RRI) and QT interval were measured after recording 5 min of the digitized electrocardiography. Then, the QT intervals were corrected with Bazett's formula (QTc). QTVI was calculated through the following formula: QTVI = log10 [(QTv/QTm2)/(RRIv/RRIm2)], QTv/RRIv: variance of QTI/RRI, QTm/RRIm: mean of QT interval/RRI.
RESULTS
Cirrhotic patients exhibited an elevated QTVI. In particular, Child class C patients had a significantly increased QTVI compared to Child class A patients and the control subjects in the supine position. However, the head-up tilt test did not cause a significant difference in QTVI in relation to the severity of ESLD.
CONCLUSIONS
Myocardial repolarization lability was significantly altered in end-stage liver disease. Our data suggest that the severity of ESLD is associated with the degree of the alteration in the QT variability index.

Keyword

End-stage liver disease; Head-up tilt; QT interval; QT variability index

MeSH Terms

Arrhythmias, Cardiac
Child
Death, Sudden, Cardiac
Electrocardiography
Heart Diseases
Humans
Liver Diseases*
Liver*
Supine Position