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

• Published in: Korean journal of anesthesiology Vol. 66; no. 3; pp. 199 - 203
• Main Authors: Huh, In Young, Park, Eun Sun, Kim, Kang-Il, Lee, A-Ran, Hwang, Gyu-Sam
• Format: Journal Article
• Language: English
• Published: Korea (South) The Korean Society of Anesthesiologists 01.03.2014; Korean Society of Anesthesiologists; 대한마취통증의학회
• Subjects: Clinical; end-stage liver disease; head-up tilt; qt interval; qt variability index; 마취과학; QT interval; Head-up tilt; QT variability index; End-stage liver disease
• ISSN: 2005-6419; 2005-7563; 2005-7563
• DOI: 10.4097/kjae.2014.66.3.199

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. 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. 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. 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.